Manual transmission vs. Automatic

JREwing78 · January 17, 2011, 10:11:20 PM

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.

agentsteel53 · January 17, 2011, 10:13:53 PM

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.

corco · January 17, 2011, 10:16:26 PM

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.

agentsteel53 · January 17, 2011, 10:20:24 PM

it is the transition from low RPMs to high that is liable to spin you out... so shift gear before it becomes critical!

corco · January 17, 2011, 10:24:37 PM

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)

agentsteel53 · January 17, 2011, 10:41:58 PM

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.

AZDude · January 22, 2011, 08:20:15 PM

I prefer an automatic. I do know how to drive a manual though.

Crazy Volvo Guy · January 28, 2011, 06:34:17 AM

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.

Henry · 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.

Crazy Volvo Guy · 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

Henry · February 03, 2011, 09:45:29 AM

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!

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Manual transmission vs. Automatic