What does everyone prefer, manual, or automatic? I prefer manual myself. Manuals are a lot more fun to drive, and give my left foot something to do. My first car of my own was a 1991 Ford Escort 5-speed, and was my favorite car simply because it was a manual. Now I'm forced to drive a boring minivan with an automatic simply so my wife is able to drive it if necessary. I say she should have learned to drive a manual! I can also remember my dad teaching me how to drive a manual in his pickup while I still had my learner's permit. Talk about being thrown into the fire!
Manual; chiefly for considerations of economy, increased vehicle control, and snob appeal.
I learned on a manual and have almost only driven manual cars. Both my parents' cars are manual, and so have been the two cars I've had so far.
When I drive an automatic, I feel sort of out of my element, like I don't have the control I should have on the car, c hanging gears when I don't expect it... I don't feel at ease with that, it gets on my nerves.
All my cars have been manual. I have driven automatic rental cars. Given the choice I would have an automatic but it would need a big engine. Small automatics I've driven are gutless and constantly need kicking down to extract what little power there is. Automatics also come in handy when taking pictures on the move, especially in heavy traffic where a manual requires constant gear changing.
How about both combined? Generally I prefer a manual over automatic, but IMHO nothing is better than both combined. Not sure what the technical term is in the industry, but at Opel (Vauxhall) it's called Tiptronic, as in, it is automatic, but if you want to change gears, you still can. Best solution for city traffic when you want the manual option but with all the stop-and-go traffic are just sick of having to use the clutch so much.
Have an automatic right now, but I want the next car to be a manual for economy, vehicle control, and theft deterrent. Yes, you read that right, theft deterrent. Since they are rarer in the US than Europe, most learn to drive an automatic and never a stick. Most US car thieves can't even drive a stick!
Quote from: DAL764 on January 07, 2011, 06:39:29 AM
How about both combined? Generally I prefer a manual over automatic, but IMHO nothing is better than both combined. Not sure what the technical term is in the industry, but at Opel (Vauxhall) it's called Tiptronic, as in, it is automatic, but if you want to change gears, you still can. Best solution for city traffic when you want the manual option but with all the stop-and-go traffic are just sick of having to use the clutch so much.
Generically, they're called manumatic transmissions. They're nothing more than a standard, computer-controlled automatic transmission that has a mode to allow the driver to manually shift gears. They use a torque converter like a normal automatic, not an automatically-controlled clutch like some people think.
I know how to drive manuals, but I've never owned one. I enjoy the novelty of it, but I worry I would get annoyed if I had to drive one daily.
Another cool technology is the continuously variable transmissions. They don't shift because they're able to adjust the gear ratio continuously. The benefit is that the car can accelerate by changing the gear ratio, leaving the car's engine at a more constant RPM. This can either help fuel economy or increase power (or both).
I always rent an automatic (no choice here in the US) but if I were to buy a car, I'd make it manual, just for the reliability and improved gas mileage. My last owned car was an '89 Escort five-speed, and even at 241000 miles it was getting me 43mpg!
I have to admit I've never driven a car with automatic transmission. In Europe you get your driving lessons in a manual transmission unless you're severely incapable of manual transmission, in that case you can get driving lessons in automatic, but a note on your drivers license will tell you you are not allowed to drive a car with manual transmission.
In Europe the more expensive cars often come with automatic transmission, but because of our high car taxes (Netherlands: 60%) a large proportion of the population cannot afford such cars.
Increasingly common are semi-trucks with automatic transmission, I've noticed they can accelerate somewhat faster because transmission time is much shorter.
Manual for sure, especially in bad weather. There's nothing worse than driving up or down a steep, snow packed hill in an automatic when the roads are bad knowing that the car may at any time shift gears and cause the wheels to spin, throwing you out of control. Being able to pick your own gear is always better on hills. From a stop on a slick surface, a manual is easier too because you can regulate the amount of power that goes to the wheels with the clutch instead of just lightly tapping the gas and spinning your tires. With proper clutching, you can easily drive a RWD vehicle with bad tires on 6 inches of ice/snow. You can't do that with an automatic.
Beyond that, they're just more fun to drive. Any really boring car (even a Corolla!) can be instantly made at least somewhat engaging to drive just by adding a clutch pedal. I definitely feel more "one" with the road (and think I'm a much better driver) when I have a stick.
I've driven manumatics, and they're nice on slick hills and things when you want to have full control over your car's gearing, but they just aren't as fun- it feels like driving an appliance IMO. If I'm not in a situation where I need it, I just stick with the automatic gearing. They do give you the safety benefits of a manual when needed and the convenience of an automatic when desired, so that's nice.
The only time I prefer an automatic is in stop and go traffic. I hate having to constantly clutch- I feel like I'm just burning it out, and that's annoying.
My parents made me learn on a manual (on bad roads too! My learner's permit time was during the winter in the mountains of Idaho. I didn't drive on bare pavement more than once or twice before I got my license. but that's another story), and I thank them a lot for it. I feel like that gave me an awareness and control of the car that just couldn't have been replicated if I learned on an automatic. Driving is too easy with an automatic- a manual requires you to be focused and alert, especially when you're first learning.
I really do not like manual transmission. It is a pain in the ass. My theory is why do it the hard way when you can do it he easy way. The worst thing about manual vehicles is that they roll back when you take off on an incline. This increases the chances for a mishap. I 've driven a Peterbuilt dump truck with an automatic. It is really nice. This truck had buttons for manual shifting if it were needed. The only time we would use it really was on ice & snow.
QuoteMy theory is why do it the hard way when you can do it he easy way.
My theory is that the hard way makes you pay more attention to the road
QuoteThe worst thing about manual vehicles is that they roll back when you take off on an incline.
Not if you know what you're doing (I haven't driven a semi in fairness- the biggest manual I've driven was a big block early 90s F-350- but I have never seen a semi roll back)
it's a lot easier to stall a small car than a large one... therefore, with the large vehicle, for the same likelihood of stalling, you can drop the clutch a lot faster to avoid roll-back. So, you're much likely to experience severe roll-back with a small vehicle.
I...disagree with that. Driving the big block F-350 was a lot harder than driving the little four-banger Dodge Colt I used to have. The F-350 had so much power that you had to clutch just right or it died, and the clutch was really heavy (the left leg hurt after a day of driving it in stop and go), whereas the Colt I could pull the clutch halfway out before it even considered stalling- you could even go from a stop without using the gas if you did it slowly enough. Same with my 4-cylinder Jeep. I don't think I could have done that in the F-350.
Quote from: Brian556 on January 07, 2011, 06:07:58 PM
The worst thing about manual vehicles is that they roll back when you take off on an incline. This increases the chances for a mishap.
I usually cheat and use the handbrake on an incline :cool: I always had a harder time backing up with a manual than I did with hills.
Quote from: corco on January 07, 2011, 06:49:20 PM
Driving the big block F-350 was a lot harder than driving the little four-banger Dodge Colt I used to have.
might just be an implementation thing.
My frames of reference are the '89 Escort, and a 1979 International Harvester Scout with I believe the 345 engine (though it may have been the 302). The International was a breeze to drive - my friend who owns it even once took it off in third just to demonstrate that it could be done.
The only time I stalled the International was when I forgot to take off the emergency brake. Oops. Even the very first time I drove it, and it was parked in an uphill parking spot, I got out without any difficulty despite having no a priori knowledge of the clutch.
(as for the handbrake thing - I did that for a little while as I got used to the Escort, but then decided it was much simpler to attempt to synchronize two processes - gas and clutch - instead of three, and forgot about the e-brake.)
Quote from: corco on January 07, 2011, 06:49:20 PM
whereas the Colt I could pull the clutch halfway out before it even considered stalling- you could even go from a stop without using the gas if you did it slowly enough.
I do not believe I could've pulled it off with the Escort. I did once take off in 2nd though, not realizing what I'd even done until it came time to shift to third.
I've never driven a stick and have no interest in learning. I see no real benefit to it.
Especially since nowadays with computer control chips and CVTs, manuals aren't even more fuel efficient anymore. On some cars, the MPG rating on the manual is actually less.
QuoteI do not believe I could've pulled it off with the Escort. I did once take off in 2nd though, not realizing what I'd even done until it came time to shift to third.
I could take off from fourth in my Jeep with some super burnouttheclutch clutchwork. That car has the most forgiving surprisingly forgiving gear ratios ever
Every car I've purchased for myself has been a manual. I wasn't eliminating automatics from consideration this last time around; it's hell in traffic jams to deal with a stick. But for all the reasons others posted, and because it was reasonably priced, I ended up with another stick.
I actually commuted 80 miles a day on a manual transmission without a working clutch for a couple months (blown clutch slave cylinder prevented disengagement). Trust me, you get DAMN good at driving when you have to match engine speeds between gears without disengaging the clutch.
I have driven both manual and automatic transmissions,given a choice I like
automatic better for stop and go big city traffic also I have had to replace clutch 4 times in the Ford van I had that was a manual transmission
while the vehicles that I had that were automatic transmissions
didn't have any transmission problems with them.
what I do like the idea of though is a manual transmission
with paddle shifters instead of stick and no clutch peddle
just slap one paddle to shift up and the other to downshift
Quote from: corco on January 07, 2011, 06:49:20 PM
I...disagree with that. Driving the big block F-350 was a lot harder than driving the little four-banger Dodge Colt I used to have. The F-350 had so much power that you had to clutch just right or it died, and the clutch was really heavy (the left leg hurt after a day of driving it in stop and go), whereas the Colt I could pull the clutch halfway out before it even considered stalling- you could even go from a stop without using the gas if you did it slowly enough. Same with my 4-cylinder Jeep. I don't think I could have done that in the F-350.
Probably just a bad clutch. I have a 97 Honda Accord that behaves exactly as you describe. The reason is that it was the first model to use a hydraulic clutch and the kinks weren't worked out yet. It's particularly bad in wet weather.
As mentioned, manuals are better in snowy weather and hills. There are plenty of steep hills east of Rochester south of Irondequoit bay (the most traveled portions are on NY 404, NY 286, and NY 441); most people have to ride the break to go down them, but I can simply take my foot off the gas and enjoy the ride. I can also keep the speed a lot more constant by downshifting on the way up without having to floor the accelerator. Downshifting is also great if you have to do something like drive I-81 in tug hill while that area is in the middle of a blizzard.
The best way to learn to start on a hill is to find a very steep hill that doesn't see much traffic (Orchard Park Blvd/Glen Haven Rd is a good example in the Rochester area) and just keep stopping and starting.
Automatic, since I don't know how to drive a manual. I did originally tried learning to drive a manual when my mom had a Mustang in the early 90s, but the car was on its last throes and she ended up buy an automatic Chrysler.
Automatic because I only have so many hands. One has to stay on the wheel, and if the other is shifting, there are no photo opportunities.
Manual. Dad insisted on it for me, my brothers, and even mom.
Quote from: AlpsROADS on January 08, 2011, 01:11:25 PM
Automatic because I only have so many hands. One has to stay on the wheel, and if the other is shifting, there are no photo opportunities.
I've had to steer, shift, take photos, and hold a busted door closed before. that was its own variant of fun.
Quote from: agentsteel53 on January 08, 2011, 03:07:20 PM
Quote from: AlpsROADS on January 08, 2011, 01:11:25 PM
Automatic because I only have so many hands. One has to stay on the wheel, and if the other is shifting, there are no photo opportunities.
I've had to steer, shift, take photos, and hold a busted door closed before. that was its own variant of fun.
That must mean a new car is in order :P
Automatic for me - and those electronic manuals - useful for climb and drop to maintain speed and not worry about a cop chasing you down to make a profit. (as speed limit drops tend to be at the bottom of a hill where I'm at.)
You really do not need automatic transmission to be able to make pictures while driving. In fact, I think just about any European road enthusiast drives stick and is still able to make good pictures from behind the wheel. If you're at a constant speed you don't need to shift gears anyway, and if you do have to do that, you can always shift somewhat later by disengaging the clutch.
in this case, the car was a rental. note to self: when in the interior of Iceland, open the door into the wind so it doesn't rip out of my hand.
QuoteYou really do not need automatic transmission to be able to make pictures while driving. In fact, I think just about any European road enthusiast drives stick and is still able to make good pictures from behind the wheel. If you're at a constant speed you don't need to shift gears anyway, and if you do have to do that, you can always shift somewhat later by disengaging the clutch.
I started my road-enthusiasm with a manual, and it's really a non-problem once you get used to it
Manuals seem unappealing to me because when I'm on the road I want to be concentrating on things like traffic flow, signs, and possible hazards, not the implementation of my car's propulsion system. The car should do as much of the work as possible so I can focus on providing the sapience to make decisions it cannot.
actually I've always thought that there is such a correlation between road situation and how one should be operating their transmission, that I've advocated that a manual transmission be required for all driver's license examinations.
I second what Jake says and would add that, especially in the instance of hazard avoidance, having more control over your propulsion system can make it much easier to perform evasive maneuvers- if the car chooses what gear to be in for you, it will often pick the wrong gear. Once you're used to driving a stick, you're likely to often be baffled by what gear your car is in when driving an automatic and realize that it's just not the right/safest gear for the car to be in at any given point- especially on terrain. The shift intervals on an automatic transmission pretty much assume flat ground.
Quote from: corco on January 08, 2011, 07:46:43 PMI second what Jake says and would add that, especially in the instance of hazard avoidance, having more control over your propulsion system can make it much easier to perform evasive maneuvers- if the car chooses what gear to be in for you, it will often pick the wrong gear.
I don't think this observation holds universally true. It really depends on the design of the automatic transmission. There is typically provision to limit the gear range from first to two or more gears down from top gear, and some automatics do allow direct gear selection. My 1986 Nissan Maxima GL had an automatic transmission which could be constrained to remain in first gear, which was useful for descending very steep hills (e.g. Marin Avenue in Berkeley, California, with a downhill grade somewhere around 20%--I could descend that in first gear at 25-30 MPH and 5000 RPM). I tend to worry more about transmissions which don't allow gear constraint below second gear, since those can easily overspeed on very steep downslopes.
QuoteOnce you're used to driving a stick, you're likely to often be baffled by what gear your car is in when driving an automatic and realize that it's just not the right/safest gear for the car to be in at any given point- especially on terrain. The shift intervals on an automatic transmission pretty much assume flat ground.
I can't speak for all experienced drivers of automatics, but I for one don't usually have any trouble knowing within a gear or two which gear ratio is actually in use. I definitely know instantly when the gear is too high, and I am very quick to take appropriate action, either by shutting off the overdrive or moving the shift lever to a lower gear range. But in general I try to anticipate rather than react--this becomes much easier with experience on automatics, just as it does on manuals.
Shift intervals on automatics don't "assume" flat ground. The shift points are set dynamically according to a number of variables, including throttle position, RPM, engine vacuum, etc. Experienced drivers of automatics usually know how to manipulate gear choice for a given situation using various positions of the throttle pedal and shift lever. Even more experienced drivers (with some knowledge of basic shadetree mechanic stuff) know how to adjust the throttle cable to "sweeten" shifts. (I did this in my Maxima and, as a result, managed the feat--fairly unusual for this particular model--of reaching 227,000 miles without a single transmission repair.)
On the other hand, experienced drivers of manuals who are naive to automatics tend to make rookie mistakes. One old friend of mine who was used to his "Silver Bullet" (a Toyota Corolla derivative with a manual transmission) managed to burn out the brakes on an automatic minivan by going down the switchbacks at Bighorn Pass in overdrive, relying on the brake pedal to control speed, instead of downshifting to L2 to take advantage of engine braking.
In general I think it is a mistake to assume that experienced drivers of automatics are any more naive about the implications of various choices of gear ratio than experienced drivers of manuals. For this reason I support automatics-only endorsements on driver licenses only if people who take their driving tests in manuals are required to have manuals-only endorsements on their licenses.
Never learned how to drive a manual 34 years ago and there is no desire to change.
I can always tell which gear the automatic is in. the ratio of speed to RPMs (plus or minus about 400, due to the slush) nails it.
without a tachometer it's a bit more of a guess but usually I'm aware, as it is a function of the engine sound.
the thing is, I tend to be able to cajole the correct gear out of an automatic using just the gas pedal and the shifter maybe 95% of the time (and the 5% when it doesn't happen reliably is the 5% where you need it the most, like going uphill on ice). With a manual transmission, that is 100%.
that said, how many people, who drive automatic transmissions, are aware of the "L" and "2" settings on the shifter? Probably not many. Forcing people to take the driving test using a manual transmission would build great awareness of those options.
but then again, driving tests don't have any correlation between what is important in general. Any moron can learn to drive 75 feet backwards on a dead-end residential street. Who really knows which way the car will spin when you swerve from pavement onto mud to avoid a collision in front of you, and how to correct and regain control? Hardly anyone.
And which is the more useful skill? Parallel parking, or staying alive? Hmm...
Given the advances in simulators, I would support much more advanced driving tests, since in that case a failure would not kill the student. While testing how merge onto a freeway, simulate a blow-out in one of the tires, and anyone who can regain control and park safely by the side of the road can get a license.
(For extra credit, change the tire yourself.)
I would venture that most folks who post on this forum are better...or at least more experienced and aware drivers than the general population. My mother, for instance, who doesn't know how to drive a manual has no idea what gear she is in when driving an automatic, and that's pretty obvious when she drives (she doesn't gas/let off the gas to get in the most fuel efficient gear, as an "aware" driver of an automatic would generally do).
It's not directly assuming flat ground, but there's no denying that an automatic works much better on a flat surface than it does on a hill. Automatics also vary greatly by car. Good luck shifting into L/2 while going more than 30 MPH in my Jeep Liberty- you'd burn the transmission out faster than the brakes if you try to do it. Manuals are easier to predict on a car to car basis- you just do whatever the engine speed tells you to do.
Gear manipulation is certainly feasible- I'm unfortunately stuck with an automatic now (and have had one as my primary vehicle for the last 3 years), but (at least in my opinion) it's a lot more difficult to push/let off the gas pedal and hope an engine computer decides to shift than to just do it myself. I've had the car not downshift when I've gassed and not upshift when I've left off, despite my own desires. Like Jake said, it's 95% instead of 100%
QuoteIn general I think it is a mistake to assume that experienced drivers of automatics are any more naive about the implications of various choices of gear ratio than experienced drivers of manuals. For this reason I support automatics-only endorsements on driver licenses only if people who take their driving tests in manuals are required to have manuals-only endorsements on their licenses.
I would strongly disagree with that- there are obviously some fine points in driving an automatic, but anybody who drives a stick can get in the car and go in an automatic. Somebody driving automatics cannot, 99% of the time, get in a car and drive a manual. It may just take a couple hours on backroads to get them up to snuff, but I'd much, much rather have somebody who has driven a manual but never an automatic drive a car than somebody who has never driven a manual try to drive a manual on the road the very first time.
QuoteWho really knows which way the car will spin when you swerve from pavement onto mud to avoid a collision in front of you, and how to correct and regain control? Hardly anyone.
Off topic, sure, but I strongly agree with that. I mostly thank my parents for the way they handled my learning-to-drive experience (did it in the winter on bad roads using a car with RWD by default and a manual transmission), but sneaking off to parking lots in the middle of the night with friends to spin donuts on icy parking lots was equally crucial (and if my parents would have known about it, they would have been pissed). The "just don't ever have to emergency maneuver" idea that most folks (and the police) have is nice in theory but doesn't actually occur in practice. It's good to have those reflexes sort of developed so if something does happen that requires evasive maneuvering, the driver is prepared to do it- I know if I fishtail in traffic, there's a very good chance there won't be an accident because I have the reflexes/muscle memory to recover that slide. You still try to avoid it, but things happen. Somebody who fishtails in traffic who has never done it before is at a significant disadvantage.
Quote from: agentsteel53 on January 08, 2011, 09:00:14 PMthe thing is, I tend to be able to cajole the correct gear out of an automatic using just the gas pedal and the shifter maybe 95% of the time (and the 5% when it doesn't happen reliably is the 5% where you need it the most, like going uphill on ice). With a manual transmission, that is 100%.
I think 5% is an overstatement--even 0.5% would be a bit on the high side, except for very unusual driving activity profiles. The situations where manuals have a compelling advantage are limited to those where the traction envelope is so narrow (such as the ice on an uphill slope example) that it is highly undesirable for the transmission to be allowed to "float" even within a very narrow gear range. In such marginal conditions I think it is fair to question the need to drive at all.
Quotethat said, how many people, who drive automatic transmissions, are aware of the "L" and "2" settings on the shifter? Probably not many. Forcing people to take the driving test using a manual transmission would build great awareness of those options.
Actually, no, it wouldn't. It would put unnecessary hardship on people who do not have access to manuals for learning in, and would not give drivers of manuals a chance to learn what they need to know to access lower gear ranges in an automatic. As my friend's example shows, extensive experience driving a manual is no guarantee that you will know what to do when you have to descend a hill in an automatic.
Quotebut then again, driving tests don't have any correlation between what is important in general. Any moron can learn to drive 75 feet backwards on a dead-end residential street. Who really knows which way the car will spin when you swerve from pavement onto mud to avoid a collision in front of you, and how to correct and regain control? Hardly anyone.
Driver testing and driver education in general are not particularly good at developing the higher-level executive functions necessary for safe driving--such as the prudence required not to make unnecessary trips on icy roads. A lot of European countries are incorporating hazard-perception elements to their driving tests, and while I approve of this in theory, I am unconvinced that real-world training and testing of hazard perception ability is even possible.
It is also worth noting that manuals introduce certain possibilities for dangerous driver error which do not exist with automatics. One example is pulling out the clutch in fourth gear while initiating a left turn, thus stalling out the car right in the path of an oncoming vehicle.
QuoteIn such marginal conditions I think it is fair to question the need to drive at all.
Quote-such as the prudence required not to make unnecessary trips on icy roads.
I would venture that this is highly unreasonable in a decent part of the country. If McCall, Idaho or Laramie, Wyoming had to shut down every time the roads were icy, winters would be impossible to negotiate. Drivers in these towns (among other mountain/high plains towns) just learn that ice is part of the road, learn how to drive in it, and do not allow the ice to deter them from driving. If one has to or even wants to be somewhere, they go. This isn't just a 22 year old talking, this is all ranges of the age/experience spectrum. This doesn't make us irresponsible, just practical, as local roads are covered with ice/snow >50% (>75% in McCall) of the time in the winter.
I mean, goodness, if I had to not drive and stay in every time it snowed in one of those towns because it was too icy, I would still be in high school!
On a side note, and I haven't looked at this in great detail, but it seems like McCall has a far higher percentage than normal of manual transmissions- everybody I know has at least one vehicle in their stable with a stick. I'd hazard at least 25% of vehicles have sticks (as compared to ~5% nationwide). I've never explicitly asked, but I would guess that this has to do with manuals being better in bad conditions.
Quote from: corco on January 08, 2011, 09:54:10 PMI would strongly disagree with that- there are obviously some fine points in driving an automatic, but anybody who drives a stick can get in the car and go in an automatic.
Yes, that belief is quite common, and in relatively flat terrain and unchallenging driving conditions the disparity between confidence and actual ability is not great, but it is in situations like hill descents and trying to drive an automatic on ice (yes, it is challenging, but it can be done) that the mismatch between what manual drivers think they can do and what they actually can do becomes most glaring.
QuoteSomebody driving automatics cannot, 99% of the time, get in a car and drive a manual. It may just take a couple hours on backroads to get them up to snuff, but I'd much, much rather have somebody who has driven a manual but never an automatic drive a car than somebody who has never driven a manual try to drive a manual on the road the very first time.
The other side of the coin is that someone who has driven automatics only will typically have the prudence not even to attempt to drive a manual without some time to practice clutching etc. on low-volume back roads and in parking lots. Meanwhile, a manual driver with zero experience of automatics will cheerfully volunteer for a challenging hill descent in an automatic and assume that no prior training is necessary.
That is dangerous.
QuoteMeanwhile, a manual driver with zero experience of automatics will cheerfully volunteer for a challenging hill descent in an automatic and assume that no prior training is necessary. That is dangerous.
I guess I disagree- the principle in driving an automatic down a steep hill is the same as a manual, you slow before the hill, let your foot off the gas and brake as needed. I don't know many stick drivers who downshift to the point of redlining their engine just to go a little bit slower (even in bad conditions).
Quotetrying to drive an automatic on ice (yes, it is challenging, but it can be done)
I'd say the same principle again. A manual driver is certainly going to be aware of the 2/L, and beyond that if they figure out that they can get minimal power just by letting their foot off the brake, it's exactly the same principle minus the ability to more finely regulate throttle with the clutch. Just like driving a manual, you still want to minimize braking, and otherwise it's exactly the same. You don't downshift to slow down on ice in a manual on a flat surface, you stay in the top gear and brake to slow down, which is basically what an automatic does. On a hill, you drop to your low gear before you start descending the hill in a manual, and in an automatic you slow to the point where the car puts itself in the low gear (or you put it in 2/L depending on the speed involved). Then you coast. Same deal either way.
I didn't drive an automatic until well after I got my driver's license (the driver's ed car in McCall had a stick!), but I just don't remember there being much of a learning curve, and off the top of my head I don't remember ever feeling like I was endangering myself due to the transmission. I just can't imagine that the manual->automatic curve is anywhere near as difficult as the automatic->manual curve.
Quote from: corco on January 08, 2011, 10:17:41 PMI would venture that this is highly unreasonable in a decent part of the country. If McCall, Idaho or Laramie, Wyoming had to shut down every time the roads were icy, winters would be impossible to negotiate. Drivers in these towns (among other mountain/high plains towns) just learn that ice is part of the road, learn how to drive in it, and do not allow the ice to deter them from driving. If one has to or even wants to be somewhere, they go. This isn't just a 22 year old talking, this is all ranges of the age/experience spectrum. This doesn't make us irresponsible, just practical, as local roads are covered with ice/snow >50% (>75% in McCall) of the time in the winter.
The definition of necessity is somewhat elastic. I think the distinction that is important here is that people living in Idaho, Wyoming, and other Rocky Mountain states with significant snow and ice accumulation have plenty of experience driving on snow and ice and thus have a concrete idea of their own driving abilities that they can factor into their own evaluations of whether their trips are necessary. They would also take into account the handling characteristics of the vehicles they would be using, and the full range of vehicles (automatics and manuals, small cars all the way up to truck-derived SUVs) are in use in those states. Snow removal practices along the proposed itinerary are also an important factor.
Winter maintenance practices vary considerably among regions. It is my understanding that FHWA requires a bare-pavement policy on Interstates, but the resourcing of winter maintenance operations depends on what can typically be expected given the climate in a given area and the amount of resilience the state DOT thinks it has to provide. Given basically the same ice storm in both places, a person driving I-84 in Boise is probably better off than someone driving I-40 in Amarillo because ITD has more winter maintenance equipment and tighter snow/ice clearance routines than TxDOT. (It was posted in MTR a while ago that the TxDOT Amarillo District apparently has no equipment for snow/ice removal and this forces closure of I-40 in major storms.)
Quote from: corco on January 08, 2011, 10:27:10 PMI guess I disagree- the principle in driving an automatic down a steep hill is the same as a manual, you slow before the hill, let your foot off the gas and brake as needed. I don't know many stick drivers who downshift to the point of redlining their engine just to go a little bit slower (even in bad conditions).
Nope. That is exactly what you do
not do for steep hills. It is basically what my friend did in the automatic minivan, and that is what caused the brakes to smoke and fade. Downshifting for hills does not remotely come close to redlining the engine--the Marin Avenue hill is the most extreme example I have personally tried and in first gear it didn't rev my engine past 5000 RPM, with redline being well above 6000 RPM (I think it was 7000 RPM).
On steep hills it is less important to save wear on the transmission (whether automatic or manual) by downshifting to a lower gear ratio and more important to preserve the ability to brake as you go downhill. Compressive braking also gives finer control of the car since it is not struggling to escape from your control just as soon as you slacken pressure on the brake pedal.
Post Merge: January 09, 2011, 04:56:34 PM
Quote from: corco on January 08, 2011, 10:27:10 PMI didn't drive an automatic until well after I got my driver's license (the driver's ed car in McCall had a stick!), but I just don't remember there being much of a learning curve, and off the top of my head I don't remember ever feeling like I was endangering myself due to the transmission. I just can't imagine that the manual->automatic curve is anywhere near as difficult as the automatic->manual curve.
Yes, the curve is steeper going from an automatic to a manual than it is going from a manual to an automatic. The problem is that people going from a manual to an automatic assume that there is no learning curve at all, when in fact there is, however mild it may be. It is this mismatch between expectation and reality that causes problems in challenging driving situations such as hill descents.
That's fair, to an extent. Down here in Tucson, I would be a bit afraid to go out if it snowed, not because I'm nervous about my own abilities but because ohdeargod how many of these people have never seen snow before.
And yeah, in Idaho and Wyoming we equip ourselves well- those who have the means keep at least one 4WD vehicle with studs and possibly a manual transmission in their fort, but the ones who have lived in the area for a while will often just drive whatever, provided it has the ground clearance to get out of the driveway (the thought being that 95% of snow/ice driving ability is driver ability, not transmissions/tires/drivetrains).
But yeah, your general point is fair. Obviously a snowstorm in Florida should button down the fort more than one in Montana. One thing not used in Idaho or Wyoming that is cried for by other areas (Seattle for one) is salt. Rocky Mountain states don't use salt, just sand on steep hills, but Midwest states (some of them?) use salt and folks who never get snowed on also cry salt.
QuoteDownshifting for hills does not remotely come close to redlining the engine--the Marin Avenue hill is the most extreme example I have personally tried and in first gear it didn't rev my engine past 5000 RPM, with redline being well above 6000 RPM (I think it was 7000 RPM).
On steep hills it is less important to save wear on the transmission (whether automatic or manual) by downshifting to a lower gear ratio and more important to preserve the ability to brake as you go downhill. Compressive braking also gives finer control of the car since it is not struggling to escape from your control just as soon as you slacken pressure on the brake pedal.
I guess our definition of "slow down" varied a bit. In the manual car I drive most frequently (a 4 banger Jeep with a 5000 RPM redline), I'll slow to about 20 MPH so I can put it in either 2nd or 3rd gear to go down a hill, which keeps me slow enough that I don't have to redline. You wouldn't drop it to 1st though, because then you'd redline. Compression brake as needed.
In my car (a 6 cylinder automatic Jeep with a 5000 RPM redline), I'll slow to 20 or so and either drop it into 2/L or just go down the hill, depending on the hill. Longer hills go to 2/L, but you shift before the hill starts if you need to shift. The key is to maintain a constant gear down the hill- it doesn't even really matter what gear (within reason). You can always compression brake.
Nutshell- with either a manual or an automatic, you get the car in whatever gear you want it to be in for the speed you want to go down the hill at, shift to that (it shouldn't be such a high gear it redlines), and then go down it, braking as needed. That's a little bit easier in a manual, but it can be done in an automatic.
The proper course of action really varies by hill, no matter what your transmission is.
Maybe I'm not explaining it very well-oh well. At least 60,000 miles of driving on bad, mountainous roads (including having to descend a fairly steep hill to get out of my parents house to go to high school) and I've never even almost been in the ditch. I'm confident in my abilities, but maybe not so much my ability to explain the procedure. :pan:
From 1972 to 1988, I drove only automatics. 1988-2006, only stickshifts, then I got a truck with automatic in addition to my stickshift car (which died in 2008). Now both of my rides are automatic -- manual was not an option for either model.
I did like the stickshifts for better performance and fuel economy, though I burned through a clutch while learning how to drive a stick for the first time, and also working the clutch could be miserable during my usual stop-and-go commutes. In addition, I was fortunate to have an automatic on hand while I was recovering from a broken left ankle in 2006.
Quote from: corco on January 08, 2011, 10:50:49 PMI guess our definition of "slow down" varied a bit. In the manual car I drive most frequently (a 4 banger Jeep with a 5000 RPM redline), I'll slow to about 20 MPH so I can put it in either 2nd or 3rd gear to go down a hill, which keeps me slow enough that I don't have to redline. You wouldn't drop it to 1st though, because then you'd redline. Compression brake as needed.
I am kind of surprised the redline is that low. But yes, given that constraint, slowing down before starting the descent is prudent.
Marin Avenue is a long downhill descent interrupted by benches where side streets cross. I usually shifted into first gear while turning onto it off of Grizzly Peak Boulevard (taking the turn very slow so the downshift would go smoothly) and then kept my foot off all pedals, just covering the brake so I could respond if someone crossed in front of me, and let the car choose its own speed once it "bit" into the grade. I chose first gear on the basis that it offered complete suppression of speed gains from the grade once the car reached 25-30 MPH. I think I tried second gear at first but had to give that up after just one block.
QuoteIn my car (a 6 cylinder automatic Jeep with a 5000 RPM redline), I'll slow to 20 or so and either drop it into 2/L or just go down the hill, depending on the hill. Longer hills go to 2/L, but you shift before the hill starts if you need to shift. The key is to maintain a constant gear down the hill- it doesn't even really matter what gear (within reason). You can always compression brake.
Yes, the points about getting in the correct gear before tackling the hill and then maintaining a consistent gear are important. I have been down the Bighorn Pass switchbacks twice, and both times I think I kept the car in second for the 10% slopes. (It is signed as a 10% pass but I don't think it is 10% for the entire distance. I think most of the hairpin curves are benched while the lengths between each curve have 10% slope.) I think I was happy with 50 MPH or so as long as I could slow down to 30 MPH for curves with no more than a gentle application of the brakes.
I can certainly understand where in some situations one might wish they had more direct control over what gear they're in, but those are few and far between. And most of them can be handled effectively, though not necessarily optimally, by using that "L" setting which, yes, I will grant you, people tend to forget exists.
A couple other issues worth mentioning:
- drivers of automatics (which describes pretty much everyone around here) seem to have a nasty habit of never using the parking brake. The thinking being that just putting the car in "P" is good enough, even if you're parked on a hill. The risk being taken is small, granted, but it's stupid and unnecessary. It's just one of those things. (nobody ever turns their wheels to the curb, either...)
- a manual transmission does, for what it's worth, give you the ability to start your car with a dead battery without needing jumper cables, so long as you have a hill or a second person to push.
From what I've noticed, automatic-only drivers really don't use neutral at all either. When I'm stopped at a light, even in an automatic, on a flat surface I'll usually shift to neutral and let off the brake to save on brake/transmission wear (not saying that it's bad that most people don't do it- it is an extra step that adds very little gain). That's a habit that I feel like came from driving a stick
Quote- a manual transmission does, for what it's worth, give you the ability to start your car with a dead battery without needing jumper cables, so long as you have a hill or a second person to push.
My Dad's first car in the mid-60s was a 1956 Volkswagen that didn't have a battery at all, so every time he went anywhere he had to push start it. Fortunately, a Volkswagen is light enough that he could push and start without having to use a friend or a hill, but he still had to be careful where he parked.
Quote from: Duke87 on January 09, 2011, 01:43:32 PM- a manual transmission does, for what it's worth, give you the ability to start your car with a dead battery without needing jumper cables, so long as you have a hill or a second person to push.
Hasn't that functionality been engineered out in recent models for emissions control reasons?
Quote from: corco on January 09, 2011, 02:46:46 PMFrom what I've noticed, automatic-only drivers really don't use neutral at all either. When I'm stopped at a light, even in an automatic, on a flat surface I'll usually shift to neutral and let off the brake to save on brake/transmission wear (not saying that it's bad that most people don't do it- it is an extra step that adds very little gain). That's a habit that I feel like came from driving a stick
Most automatic drivers will indeed keep the car in gear and use the brake to restrain creep because that saves on time and motion when the light changes. However, if I expect to be stopped in traffic for a considerable length of time (e.g. long train at a railroad crossing, or waiting for my direction to be given the go-ahead on a two-lane rural highway subject to one-way working while under construction), I will pop the transmission into neutral, switch the engine off, and set the parking brake.
I have an automatic. I frequently put it in park while waiting for trains or at drive-thru's.
Quote from: Duke87 on January 09, 2011, 01:43:32 PM
- drivers of automatics (which describes pretty much everyone around here) seem to have a nasty habit of never using the parking brake. The thinking being that just putting the car in "P" is good enough, even if you're parked on a hill. The risk being taken is small, granted, but it's stupid and unnecessary. It's just one of those things. (nobody ever turns their wheels to the curb, either...)
The only two circumstances I always use the parking brake are if I'm parked on a steep hill and if I'm parked on the street (even if it's flat). If I'm parked on the street without the parking brake, all it can take is one small tap from behind and the parking gear is stripped. That's an expensive repair.
Quote from: corco on January 09, 2011, 02:46:46 PM
From what I've noticed, automatic-only drivers really don't use neutral at all either. When I'm stopped at a light, even in an automatic, on a flat surface I'll usually shift to neutral and let off the brake to save on brake/transmission wear (not saying that it's bad that most people don't do it- it is an extra step that adds very little gain). That's a habit that I feel like came from driving a stick
Once the car is stopped, holding the brake down won't cause it to wear any more quickly. And the torque converter means that for an automatic in idle, if it's in drive it's stationary; if it's in neutral, the transmission is spinning. Leaving the automatic in neutral ADDS wear to the transmission.
I've never driven a full manual.
Early in my driving career, I did drive a '68 VW Bug with an automatic clutch. It still had a shift lever, but, instead of a clutch pedal, you pressed down on the stick when shifting to engage the clutch.
For me, a manual transmission does not appeal to me, having to think to coordinate the clutch and shifting would take my concentration off the road. And, as someone who has a limited ability to multitask, I like to keep my focus on the road, thank you.
As I've already said, these are strictly personal preferences and I don't think either automatic or manual is inherently better than the other overall. In certain situations, that's another story.
My brother is someone who is equally at home with automatic and manual transmissions. Even with his performance cars (Mustangs and Thunderbirds) he has had both auto and manual versions of both and can do well in either. Though, I think he still prefers manual in a performance car and automatic otherwise.
QuoteOnce the car is stopped, holding the brake down won't cause it to wear any more quickly. And the torque converter means that for an automatic in idle, if it's in drive it's stationary; if it's in neutral, the transmission is spinning. Leaving the automatic in neutral ADDS wear to the transmission.
Wait, really? My thought was always that if I let my foot off the brake on a car in drive, it rolls forward at low power. It seems to me that hitting the brake is restraining the car from going that low speed and therefore puts (very) minor wear on the brake.
Although if what you say about torque converters is true (and I have absolutely no reason to doubt you) it sounds like the tradeoff is worse for the transmission anyway. Heh, I'll stop throwing it in neutral for short periods of time then.
Quote from: mightyace on January 10, 2011, 10:48:00 AM
For me, a manual transmission does not appeal to me, having to think to coordinate the clutch and shifting would take my concentration off the road. And, as someone who has a limited ability to multitask, I like to keep my focus on the road, thank you
If you're used to it, it becomes second nature. I think most people who drive automatic don't like manual because they never really learned how to drive it, maybe tried it two or three times and it didn't work out. That is also why driving lessons in Europe are considerably more extensive. Everybody's supposed to be able to drive a manual car, though exceptions can be made. For me driving a manual car is just like walking up the stairs or riding a bike. You do it without really thinking about what you're doing.
^^^
Well, I drove that auto-clutch bug nearly every day for two years, and, while it became easier, I always had to think about shifting.
Quote from: corco on January 10, 2011, 11:29:54 AMWait, really? My thought was always that if I let my foot off the brake on a car in drive, it rolls forward at low power. It seems to me that hitting the brake is restraining the car from going that low speed and therefore puts (very) minor wear on the brake.
No. The only relevant consideration is wear on the transmission since the brakes don't actually wear unless the discs or drums are moving in relation to the pads (brakes work by friction), which happens only if the car is actually moving. I was under the impression that in most automatic cars, putting the transmission in neutral disengages a drivetrain clutch either before or after the torque converter, so the converter isn't actually spinning when the car is in neutral.
The main reason I put the car in neutral and turn the engine off for extended waits is to save fuel.
One other thing people commonly do that is not terribly bright with manuals, but is downright dumb with automatics, is to tow a car in neutral at freeway speeds with drive wheels down. When this happens everything in the automatic transmission behind the torque converter is being driven by the wheels and the wear on those components is immense at speeds above 35 MPH.
^^^
While this is generally true, there are exceptions.
The owner's manual from my old 1994 Saturn SL1 sedan say that it's OK to tow it in neutral with all wheels down.
Quote from: J N Winkler on January 10, 2011, 12:59:57 PM
I was under the impression that in most automatic cars, putting the transmission in neutral disengages a drivetrain clutch either before or after the torque converter, so the converter isn't actually spinning when the car is in neutral.
I thought the disconnection for neutral was inside the transmission - it disengaged the gears so that the input shaft wasn't connected to the output shaft. In that case, the torque converter would be driving part of the transmission. If you're just holding the brakes on while in drive, the output shaft of the transmission is locked to the wheels (i.e. stopped), so the torque converter spins without turning the tranny at all.
Quote from: corco on January 10, 2011, 11:29:54 AM
Wait, really? My thought was always that if I let my foot off the brake on a car in drive, it rolls forward at low power.
That's true. You can think of a torque converter as a pump and an old-time water wheel. The engine drives the pump which sends liquid over the water wheel connected to the output shaft, which is then connected to the transmission. When the car is stopped, the brakes hold the wheels still, which holds the transmission still, which holds the "water wheel" still. The pump is still pumping fluid to it, but because the "water wheel" is locked, the fluid passes over it. As soon as you let up on the brakes, the "water wheel" starts turning again.
The brakes are holding the car stopped. It's the friction between the brake pads and the rotors that cause the pads to wear down. When the wheels aren't turning, there's no sliding friction between the pads and the rotors so there is no ware on the brakes.
Quote from: corco on January 08, 2011, 10:50:49 PM
Down here in Tucson, I would be a bit afraid to go out if it snowed, not because I'm nervous about my own abilities but because ohdeargod how many of these people have never seen snow before.
indeed - though not quite as bad as SoCal drivers, who are hosed even in the rain. They seem to be blissfully unaware of the need to slow down... I've been passed by people doing over 100 in heavy rain, unable to make the connection between their own behavior, and the fact that every couple miles, there's a highway patrol vehicle parked by the side of the road, with the cop peering down the ravine past the huge hole in the guardrail.
For what it's worth, the fact that I know how to drive a stick just secured me a job wherein I will occasionally have to valet park cars (very nice cars, at that)- so take that, automatic drivers. :sombrero:
OKAY FOLKS:
1) In an automatic, neutral definitely disengages something. When I'm idling in drive with my foot on the brake (yes, it will roll forward otherwise), there is something growling and grumbling below me that stops as soon as I shift into neutral. Count me among the few auto drivers who makes proper use of neutral (note: it's NOT for long downgrades), and I was taught by another road enthusiast.
2) Parking brakes are not necessary on flat surfaces, but they are necessary on inclines regardless of what you drive, and anyone who doesn't set one is not just asking for damage, but will damage the next thing downhill, which is a shame.
3) How to drive an automatic downhill: Know your car. I know that 1st gear will limit me to 15-20, 2nd gear will limit me to 30, 3rd gear will limit me to 45-50, etc. I happen to have a manumatic so I can select any gear from 1-6 and my transmission will not exceed that gear (but it will go lower to avoid stalling the engine). If the hill is less than two miles long and it's dry out, I'll just keep it in "6" and brake every so often. BUT, the way I brake is by reducing a large clump of speed at once (say from 70-50) and letting my car rebuild the speed. That lets the brakes recover and cool down before the next time. People who ride their brakes gently all the way down are the ones who die. (I try to do it when the grade flattens slightly - there are always variations in grade.)
4) How to drive an automatic on ice: You don't have clutch modulation, so you need a sensitive right foot and a throttle that's not jumpy. So you won't get that big V8 going, that's for sure. My strategy is to let off the brake and see if the car rolls on its own. If not, I tiptoe into the throttle until the car starts moving, hold until the wheels and revs match, ease a little more, hold, repeat until I've gained speed.
5) How to slow down on ice: Downshift! Get in the lowest gear you can. My automatic prevents me from going above roughly 4K rpms when I downshift, which isn't the most helpful in snow - that's why I start slowing and downshifting well in advance of any hill. Brake softly but steadily while on relatively flat ground to minimize the gear number you can choose. When approaching anything resembling a stop or turn, I want my car in 1st gear and I will prepare at least 1/4 mile in advance to get my car slow enough for that shift.
If we had some sort of recommend button, I would recommend this post. Well put on all counts, Steve.
The most important aspect of slowing down on ice is to avoid going too fast in the first place. The second most important aspect of slowing down on ice is to not do it when it isn't actually necessary.
A common mistake people make is that they'll be driving down the highway, spot a patch of ice, panic, and hit their brakes. This is unwise. Try to brake at high speed on ice and you can lose control. Don't touch either pedal and you will roll right over it without incident. You do, of course, have to slow down if the ice is on a curve, but be sure to take your foot off the brake before you hit it. Braking on ice at high speed while turning is just asking to spin out.
99% of driving on ice is just anticipating about 5-10 seconds in advance (as opposed to oh, like 2 or 3 seconds in advance on dry pavement). If you're in a vacuum on a wide open but totally slick and straight stretch of road with no chance of any traffic or animals or other hazards, you can safely drive as fast as your car can possibly go, even with completely bald tires (provided you can get your car going that fast in the first place).
Of course, that situation doesn't ever exist. There's always some hazard. If I'm a wide open stretch of road in daylight (where I can see a decent amount in advance)- like WYO 487 wide open, where you're not likely to even see another car and you can see about a mile ahead. I'm totally comfortable going 60 MPH. On an urban freeway, where there's tons of hazards, people really shouldn't be going more than 30 or so, but they do, so for me the easiest way to drive in snow on urban interstates is to stay in the gaps (traffic tends to travel in clumps- if you get between those clumps you can safely go the speed the clumps are going).
Slowing down is just fine as long as you don't use your brake to do it, and if you do you do what Alps alluded to and slow down incrementally as opposed to slamming your brakes to do it. Near the house I grew up in in Idaho is a fairly long, steep hill that's completely straight. Dozens and dozens of tourists end up in the ditch on the side of that hill every winter (enough that a buddy of mine and I used to sit by that hill after snowstorms on weekends and charge out of countiers $20 to pull them out of the ditch with the aforementioned F-350). The problem was that they didn't slow enough before entering the hill, got up to 35-40 about halfway down the hill, decided they'd rather be going 25, hit their brakes, and went in the ditch. Since it's a straight hill, it's much safer to just accumulate speed, descend, and worry about slowing down at the bottom of the hill (ideally you'd slow before the hill, but hey, that's too much to ask).
I've made a habit of almost always letting my foot off the gas when either being passed or encountering oncoming traffic when the roads are slick- that seems to work pretty well to give me just a little bit of extra reaction time if I need it.
Another thing to remember is that sometimes acceleration is the best option if you lose control. Sometimes if you start fish tailing and you for some reason can't recover (like you're towing a trailer), you can actually gun it to regain control. Braking lands you in the ditch 100% of the time.
In the trailer example, I actually saw a guy do it on I-80 in Wyoming last winter. It was windy and the roads were bad and he was towing a light trailer and the thing started fishtailing and was near the point of jack-knifing and rather than brake he slammed the gas and the trailer straightened out and he regained control. If he would have braked, he would have been rolled over in the median. That was probably the single smartest driving maneuver I've ever seen, because the reflex would be to slow down for most people.
The way I drive on ice in a nutshell is to keep three simple things in mind:
1) My car doesn't have brakes
2) Every other car has no traction and is going to slide into me
3) I will slide occasionally, so it's good that I go to parking lots and spin donuts in the middle of the night to learn how to react*
As you do it a lot, you gain confidence, and eventually you get to the point where you aren't going to drive yourself into the ditch. If I drove myself into the ditch on an open stretch of road, that would absolutely be the most embarrassing thing that has ever happened to me. I have enough experience that I shouldn't ever do that. For that reason I tend to avoid interstates when it snows- at least in the rural west you're more likely to encounter a road where you're the only car on the road (this probably doesn't apply back east) and hazards are significantly minimized. If I go in the ditch, I would have had to put myself in the ditch. I'd go so far as to say that I'd rather drive an unplowed backroad than a plowed interstate.
Plowed roads tend to give people a really false sense of security, when in reality the driving conditions aren't that much different. I'd rather drive on packed unplowed snow than plow ice, because packed snow is obvious. Everyone knows that when the road is white you go slow. When the road has some pavement and some ice and a lot of black ice because the plow came through, a lot of drivers decide that it's OK to speed up.
*The notion that a lot of winter drivers have is "I should never slide." And no, you shouldn't in theory, but it will happen. The absolute best winter drivers in the world slide on occasions. If you have the reflexes developed to recover from it, that should be no problem at all and you'll recover without any sort of incident, so best to prepare yourself for it if you're going to drive in the winter.
Quote from: AlpsROADS on January 10, 2011, 08:09:57 PM
2) Parking brakes are not necessary on flat surfaces, but they are necessary on inclines regardless of what you drive, and anyone who doesn't set one is not just asking for damage, but will damage the next thing downhill, which is a shame.
Good post. I'd recommend a parking break on flat surfaces though if there's a chance you'll get hit from the front or behind, like when you're parked on a street. The parking brake can make the difference between needing a just new bumper and needing both a new bumper and a new transmission. It's not unheard of for the parking pin in the tranny to get sheared off if hit just right.
I forgot to add earlier: While I'm an engineer and am obsessive about knowing how things work, I'm neither a mechanic nor a mechanical engineer. Feel free to yell at me if I'm incorrect about anything :-D
Quote from: AlpsROADS on January 10, 2011, 08:09:57 PM2) Parking brakes are not necessary on flat surfaces, but they are necessary on inclines regardless of what you drive, and anyone who doesn't set one is not just asking for damage, but will damage the next thing downhill, which is a shame.
And FYI, there might be an incline you didn't notice... which is why I always put my parking brake if I get out of my car, regardless of the surface. Two days ago, I was stopped on the side of the highway to refill my windshield washer tank. My friend, who I was following, parked in front of me and got out of the car to chat with me. As I'm in front of my car, pouring the fluid, his car's rear started to roll backwards and its bumper suddenly hit and squeezed my legs. While I got out of there with only a bruise and barely any pain, things could have been worse, say, if he drove something bigger than his small Mazda MX-3.
Quote from: corco on January 10, 2011, 10:46:21 PM
Another thing to remember is that sometimes acceleration is the best option if you lose control.
this. from a feedback systems engineering perspective, it is obvious, but a lot of people have no idea. When you give your car forward impetus, it will serve to cancel out your lateral movement (fishtailing).
a lot of the time, when losing control, a brief moment of acceleration is exactly what you need. like the previous situation I mentioned about swerving off the road onto mud - at that point, you turn *into* the spin (as it's the muddy tires that have made you lose traction), floor it for a split second to get your wheels grabbing forward, straighten out again while you have traction, and then when your other two tires hit the mud too, turn back, aim towards the road, back off the gas (maybe even take the car entirely out of gear), hold the wheel steady, and rejoin the concrete.
and watch the fireworks as the two colliding cars ahead of you are now the two colliding cars behind you. behold the morons, but don't become one... all in about 1.5 seconds, and that beats the shit out of knowing how to parallel park.
Quote from: AlpsROADS on January 10, 2011, 08:09:57 PMIn an automatic, neutral definitely disengages something. When I'm idling in drive with my foot on the brake (yes, it will roll forward otherwise), there is something growling and grumbling below me that stops as soon as I shift into neutral. Count me among the few auto drivers who makes proper use of neutral (note: it's NOT for long downgrades), and I was taught by another road enthusiast.
The thing "growling and grumbling" is the torque converter, which is essentially a fluid coupling consisting of two specially formed plates. One plate is connected to the engine flywheel while the other is connected to the driveshaft (or drive axles) through the transmission. It is not a rigid connection like the dry clutch in a manual transmission. Torque converters are designed to have high slip at low RPM; this is what allows you to idle in Drive on your brake while the input RPM is the engine idle speed and the output RPM is zero. However, the slip drops to 5% or less at 2000 RPM or faster. In fact, if your torque converter is working correctly, you should be able to stall your engine by revving up to 2000 RPM or faster while standing on the brakes so that the car cannot move. (This is called the "torque converter stall test" in auto repair contexts and is typically not done unless absolutely necessary because it places immense strain on the transmission and can even cause transmissions in marginal condition to fail altogether. Even setting the parking brake and then forgetting to release it before hitting the throttle in Drive can kill such transmissions.)
There is a dry clutch somewhere between the engine and the driveshaft (or drive axles) which is disengaged to put the transmission in neutral. The issue is really whether this clutch is located between the flywheel and torque converter, or between the torque converter and the planetary gearsets. I think the logical location for this clutch would be between the flywheel and torque converter since otherwise both parts of the torque converter would be freewheeling to no apparent purpose, but I do not know for a fact that this configuration is used and suspect it may in fact vary from model to model. To confuse matters even more, the vast majority of automatic transmissions have had lockup overdrive since the mid-1980's. The traditional implementation is a dry clutch that engages in top gear to bypass the torque converter and thus allow the car to cruise at freeway speeds with zero slip at relatively low engine RPM values (usually around 2000 RPM at 60 MPH).
QuoteParking brakes are not necessary on flat surfaces, but they are necessary on inclines regardless of what you drive, and anyone who doesn't set one is not just asking for damage, but will damage the next thing downhill, which is a shame.
Realjd's point about protecting the parking pawl when parking on the street is a good one, as is Dr. Frankenstein's about deceptive inclines. There are some locations in Alberta (I forget where, but one example has been called out in AAA TourBooks) where you can stop your car on what appears to be a downhill incline, put the transmission in neutral, and then observe the car roll backward.
Personally, I always set the parking brake when parking my personal car, regardless of whether I am on an incline or not. If I am driving someone else's car, I also set the parking brake unless I am returning the car to a place where the owner (or somebody else) is likely to be the next person driving it and would have no reason to expect an "ordinary" person (i.e., not me) to set the parking brake.
QuoteHow to drive an automatic downhill: Know your car. I know that 1st gear will limit me to 15-20, 2nd gear will limit me to 30, 3rd gear will limit me to 45-50, etc. I happen to have a manumatic so I can select any gear from 1-6 and my transmission will not exceed that gear (but it will go lower to avoid stalling the engine). If the hill is less than two miles long and it's dry out, I'll just keep it in "6" and brake every so often. BUT, the way I brake is by reducing a large clump of speed at once (say from 70-50) and letting my car rebuild the speed. That lets the brakes recover and cool down before the next time. People who ride their brakes gently all the way down are the ones who die. (I try to do it when the grade flattens slightly - there are always variations in grade.)
While that approach will generally work, I prefer not to even get in a situation where I need to consider braking pattern as a strategy for avoiding fade. My general approach is to settle on a steady speed which I expect to be able to sustain safely for the majority of the grade, and then choose the highest gear which will allow me to maintain that speed with no speed gain without having to use the brakes. Then I time shifts for smoothness. It is not the high RPM that places wear on the transmission; it is harsh changes of gear. Engine RPM can go quite high when descending grades in low gear, but as long as the engine is under redline, this is unimportant since the engine has continuous positive-pressure lubrication and oil pressure goes up with engine RPM. Coolant temperature will also drop (almost to thermostat-opening temperature), which can be helpful if the engine is running hot from a prior hill climb.
Quote from: J N Winkler on January 11, 2011, 06:35:31 PM
WThere is a dry clutch somewhere between the engine and the driveshaft (or drive axles) which is disengaged to put the transmission in neutral. The issue is really whether this clutch is located between the flywheel and torque converter, or between the torque converter and the planetary gearsets. I think the logical location for this clutch would be between the flywheel and torque converter since otherwise both parts of the torque converter would be freewheeling to no apparent purpose, but I do not know for a fact that this configuration is used and suspect it may in fact vary from model to model. To confuse matters even more, the vast majority of automatic transmissions have had lockup overdrive since the mid-1980's. The traditional implementation is a dry clutch that engages in top gear to bypass the torque converter and thus allow the car to cruise at freeway speeds with zero slip at relatively low engine RPM values (usually around 2000 RPM at 60 MPH).
I've never heard of a "dry clutch" so I did a bit of research. Apparently, inside most torque converters is a "lockup clutch" that engages automatically at around 40 mph to lock the input side to the output side to prevent slip.
Inside automatic transmissions is a "clutch pack". It's connected directly between the input shaft of the automatic transmission and the planetary gears. If the car is in neutral, the nothing except the input shaft is spinning. Apparently this comes after the torque converter since it's also used when the transmission shifts.
So it looks like the standard car is set up:
Engine -> Torque Converter -> Flywheel -> [Clutch Pack -> Planetary Gearset] -> Wheels
Interestingly, there's also a "one-way clutch" that works like a bicycle's freewheel. It's allows the car to coast if in 1st gear in Drive (not L though).
The only reference to "dry clutch" I could find was in reference to manual transmissions, and an obscure transmission technology that some German cars use: http://en.wikipedia.org/wiki/Dual_clutch_transmission (http://en.wikipedia.org/wiki/Dual_clutch_transmission)
A few other sources:
http://www.familycar.com/transmission.htm (http://www.familycar.com/transmission.htm)
http://www.familycar.com/transmission.htm (http://www.familycar.com/transmission.htm)
http://auto.howstuffworks.com/automatic-transmission.htm (http://auto.howstuffworks.com/automatic-transmission.htm)
None of the usual car repair sources include much info on transmissions for obvious reasons. My Haynes books barely mention them.
Quote from: realjd on January 11, 2011, 07:07:50 PMI've never heard of a "dry clutch" so I did a bit of research. Apparently, inside most torque converters is a "lockup clutch" that engages automatically at around 40 mph to lock the input side to the output side to prevent slip.
I was using "dry" in the sense that it operated by friction and was designed to have zero slip. This, it seems, differs somewhat from the accepted engineering usage, which considers a clutch "dry" or "wet" according to whether fluid is used. Apparently the clutches inside an automatic transmission are all "wet" though they work by friction (I think this is where the thixotropic properties of ATF come into play).
QuoteSo it looks like the standard car is set up:
Engine -> Torque Converter -> Flywheel -> [Clutch Pack -> Planetary Gearset] -> Wheels
I think this is basically correct, with the exception that the flywheel is immediately behind the engine. It has teeth on its edge, which the starter motor engages in order to crank the engine. It connects to the torque converter via a drive plate, which also has teeth and drives a governor which inputs engine crankshaft speed into the control valve body. The clutch pack and planetary gearset (including brake bands) basically occupy the entire gearbox from front to back.
QuoteNone of the usual car repair sources include much info on transmissions for obvious reasons. My Haynes books barely mention them.
Haynes, Chilton, etc. are aimed at a shadetree audience, so they basically explain only how to disconnect the transmission from the engine, but the factory service manuals have fuller information. I still have the one for my old Maxima. It has an exploded diagram of the standard automatic transaxle from front (just behind torque converter) to back (output gear for the differential), running to two pages and containing illustrations of well over a hundred distinct parts. There is also a hydraulic circuit diagram for the control valve body, which takes up a whole page and is mind-blowingly complicated but manages not to be too much more elaborate than the equivalent for a mid-1960's GM three-speed automatic which Familycar.com uses as an example.
One useful thing I did learn from a Haynes manual, which was not in the factory service manual, was how to drain and refill the transmission by removing the drain plug. Officially the transmission in the Nissan Maxima required no routine maintenance and the factory service manual didn't even document the existence of the drain plug. However, I found that sticking to a 15,000-mile interval for draining and refilling the transmission (only a smallish proportion of the total fluid content could be drained at any given time) kept performance sweet.
I like doing my own car repairs, but the only major thing that has gone wrong with my current '01 Honda Accord was a transmission problem. I figured that was above my ability level to work on and had a mechanic do it. I (thankfully!) haven't had anything to repair yet that necessitated a factory repair manual, but I'm sure it's just a matter of time before I end up having to buy one. My wife's '02 Mustang has been running similarly well, so I haven't had to do much work on it either. Back in college though, having a factory manual saved me a significant amount of money keeping my beater Camry in working order!
This has been a good discussion. It's given me an excuse to learn more about how automatic transmissions actually work. Plus, I got to learn what "thixotropy" means! As a Computer Engineer, I'm in awe over the fact that people actually designed mechanical systems as complicated as an automatic transmission.
I have driven just about every transmission type out there. For all you folks who have never driven a manual, you develop a motor memory and its second nature to the point that when you get into an automatic car, your left foot is stomping for a clutch that isn't there. Manual transmission drivers tend to do better with fuel economy because of how they drive. You coast a lot more, and anticipate shifting. You try to avoid stopping (less dealing with the clutch, stopping quickly and then starting is annoying), and nothing is more annoying then being cut off on the highway and having to downshift... ugh. You will get people mad when crawling in traffic, you want to stay in 2nd and keep moving. Sometimes that results in a gap between you and the car in front. Everyone wants to stop and go (because its easy with an automatic), with a manual, crawling at a continuous 5mph is better. Riding the clutch is BAD.
For fuel economy reasons, the manual's advantage has diminished, automatics have closed the gap and almost always have equal or better fuel economy numbers (usually better highway). My last car had a direct shift gearbox. It was a double clutch computer controlled gearbox with no torque converter. It drove like a manual without the clutch with lightning fast shifting (there is no jerk+power loss during gear changes), coming to a full stop just let out the clutch. By far the best non-traditional automatic for drivability. CVTs are blah, never cared for their rubber band driving dynamic. They just kinda loaf up to speed. I'm back to a slushbox in my current car, it seems they have made improvements since my last car with one. More gears, more fuel efficient, and shifts slightly slower then the DSG... impressive.
Quote from: AlpsROADS on January 10, 2011, 08:09:57 PM
5) How to slow down on ice: Downshift! Get in the lowest gear you can.
So, in other words, I want to use maximum engine braking? On ice? No offense, but that's a terrible idea. On ice, I want the engine out of the equation, so that I have more control over the braking force going to each wheel. So, if anything, I drop the transmission into neutral.
Once I do that, I ease into the brakes and carefully feel out the point where the tires start to skid, then ease off just enough to regain traction. If the car starts to slide sideways, I come off the brakes and steer where I want the car to go, then once back under control ease into braking again.
Quote from: JREwing78 on January 17, 2011, 08:35:00 PM
Once I do that, I ease into the brakes and carefully feel out the point where the tires start to skid, then ease off just enough to regain traction. If the car starts to slide sideways, I come off the brakes and steer where I want the car to go, then once back under control ease into braking again.
I disagree with this, simply because the inertia of the engine diminishes the acceleration by a particular factor. Since the exact point of skid is dependent on every situation (friction of ice, vertical angle, and a certain amount of luck), I would minimize all incoming adversarial variables before depending on my ability to take on the worst that the situation could possibly offer.
I know that for both manual and automatic transmissions, taking the car out of gear (putting it into neutral) causes it to become much "lighter" with respect to both the human controls and the external influences... I once slid out (out of gear, in a manual transmission) on an ice-covered level road in northern California and had the car in the middle of the intersection before I steered into the turn, found the brakes and came to a halt, and regained enough control to put the car back into gear and find my way forward.
you may be mistaking the effects of
being in gear versus the effects of
putting the car into gear. If you are not careful, the sudden applied momentum of putting the car into gear may be what loses your control - but having a car in gear, with traction, going forward is invaluable when presented with an icy surface.
Yeah, you absolutely want to minimize the process of downshifting, especially on hills, but being in a low gear to begin with is a very good thing. If you start driving down an icy hill and get to 25 or so depending on the car and drop from D to 2 (or 3rd to 2nd or whatever), you'll likely start sliding, but if you put the car into 2 before you start going down the hill, that's to your advantage.
Now, if you do downshift while you're in motion, you want to use your brakes to slow the car to the point that you can downshift without getting the RPMs above a certain level, and then you can shift without sliding and use the lower gear to hold the new speed. You want to slow with your brakes and hold the slow speed with the engine.
And then if you lose traction you definitely want to already be in gear, because you'll usually need the gas pedal to get out of it.
The post was presented to me as slowing down while on ice, in which case you don't want the engine braking to exceed the friction of the tire on the ice. Otherwise, you get one end of the car locking up while the other one's rolling, and that rarely ends well.
If you can slow down while in gear without locking up the drive axle, fine. But often, that engine braking is stronger than the friction you have on the ice, and you end up spinning out. Better to take the engine out of the equation, and slow all the wheels evenly.
yep, you just noted the hazard of suddenly slowing down upon encountering ice. A hideous lurch, and the sliding that accompanies it.
ideal stick-shift driving is to downshift well before the ice comes.
Right, you don't downshift on the ice, and if you do you do it in tandem with braking so as to keep your RPMs reasonably low (which is where a manual comes in handy), as that high RPM jump is what causes the sliding
But to me the whole downshifting thing really only applies on hills. I can agree that keeping RPMs low is generally a good policy for handling on ice on level ground, and that involves being in the highest possible gear (which is better than neutral)- if I'd normally be in 3rd gear at 31 miles an hour, I may put it in 4th on ice (on level ground), so I agree with you on that front. Then if you know how to threshold brake, which I think you mentioned in your first post, you should be able to come to a safe stop. But yeah, just look at it from an acceleration from a stoplight standpoint. On ice and level ground, it's often easier to start in 2nd than first, so the same principle applies while you're already driving.
it is the transition from low RPMs to high that is liable to spin you out... so shift gear before it becomes critical!
Right, but on a level surface you rarely gain anything by engine braking- it can help to slow down if you're at a really high RPM when you're cruising along, but at that point I look at that as a waste of gas (once again, depending on the situation- the moral of the story is that there's dozens of different "correct" ways to do it, but all are applicable in slightly different circumstances, and experience is the only thing that can teach you what to do when)
I try not to ever be cruising along at far too high RPMs - especially not while on winter roads! high RPMs are for passing loser drivers.
I prefer an automatic. I do know how to drive a manual though.
Both of my current ones are automatics. All my Turbo Volvos have been automatics to date. I'd rather have a manual, but the legacy RWD Volvo manual transmission (M46/M47) is a steaming pile. The automatics are the same units as those used in 80s/90s Toyota pickups. Needless to say, they're bullet-proof. And they actually shift properly - that is, it's crisp and firm, you can actually feel it.
On that note, Ever wondered why the Ford Taurus, Chrysler & later Honda minivans, et. al. have so many transmission failures? It's those nice smooth shifts you can hardly feel. They're accomplished by slowing the fluid flow to the clutch packs, causing controlled slippage, which generates a vast amount of extra heat & wears said clutches out prematurely. Transmission coolers will help your cause, but will only delay the inevitable. Modifying the transmission to shift properly is the only way to make it last.
Every car I've ever owned is an automatic. I really don't feel comfortable with manuals, as you run the risk of overrevving the engine if you stay in one gear too long.
Quote from: Henry on January 31, 2011, 04:28:11 PM
Every car I've ever owned is an automatic. I really don't feel comfortable with manuals, as you run the risk of overrevving the engine if you stay in one gear too long.
Uh...this isn't the 1970s anymore. Modern engine management systems have rev-limiters, preventing the engine from over-revving by effectively shutting it down for a split second and repeating that process until you let off the gas. Heck, even my 20+ year old Volvos have that feature.
Edit: here's a demonstration. http://www.youtube.com/watch?v=NGn4SaDnfAU
Quote from: US-43|72 on January 31, 2011, 08:09:49 PM
Quote from: Henry on January 31, 2011, 04:28:11 PM
Every car I've ever owned is an automatic. I really don't feel comfortable with manuals, as you run the risk of overrevving the engine if you stay in one gear too long.
Uh...this isn't the 1970s anymore. Modern engine management systems have rev-limiters, preventing the engine from over-revving by effectively shutting it down for a split second and repeating that process until you let off the gas. Heck, even my 20+ year old Volvos have that feature.
Edit: here's a demonstration. http://www.youtube.com/watch?v=NGn4SaDnfAU
Well, that changes things! :D