What type of gasoline do you use?

[ilvny]

What type of gasoline do you use?  The vehicles at my house all recommend 87 octane (regular).  My dad (worked as a mechanic and does mechanical work on my family's vehicles) likes to use 89 octane (middle-grade) because of additives that improve engine performance.  He sometimes uses 91 octane (premium).

Lately, I've been alternating between regular and middle grade because regular costs less.  From December 2012 to the end of January 2013, there was at least a $0.20 price difference between regular and middle grade in Pennsylvania.  If my Ford Explorer's fuel tank is 1/4, I have to spend at least $50 to fill it.  My dad will use regular once in a while, but he prefers middle-grade.  I have not noticed any difference in engine performance using regular or middle grade.

Types of gasoline
87 octane: regular
89 octane: middle-grade
91 octane: premium
93 octane: ultra-premium

[cpzilliacus]

I don't normally use gasoline.

But I do buy Diesel fuel.  Taxable.   40 cetane.

[bugo]

There's a Quik Trip about 3/4 of a mile from my pad that sells E0 (ethanol free) gas.  I can't remember if it's 87 or 89 octane.  It's about 12 cents more a gallon than the E10 but my car runs better on it and it gets better mileage.

[BigMattFromTexas]

Why don't you just make a thread and call it "My questions" then you can ask them all in one space instead of making 10 new threads...
BigMatt

[ilvny]

Why don't you just make a thread and call it "My questions" then you can ask them all in one space instead of making 10 new threads...
BigMatt

Because I don't come up with all the questions at once.  If I kept reediting one thread, it would confuse people who replied before the edits were applied.  I believe it's also easier to have one thread per topic than several topics in one thread.

[1995hoo]

Two of our cars call for premium, so we use 93 octane in them (91 is not normally sold here except at Sunoco). The third car gets 87. I used 87 in one of the other cars once only, in Louisbourg, Nova Scotia, because the only station in town sold only 87 and diesel. I put in $10 worth to get us to Sydney so I could refuel with the correct stuff.

[corco]

I use 87 most of the time.

In Montana the typical breakdown is 85.5/88/90+, and then in Wyoming it was 85/87/90+, as you theoretically can run one octane grade lower at high elevation. Colorado, Utah, and parts of Idaho also sell 85 as the default base grade.

I don't find my car runs as well with anything less than 86 no matter what the elevation (which I've seen in eastern Idaho and New Mexico), so I buy 88 in Montana now since I can't get 87.

I usually buy E10, but I've been driving in Canada the last couple days where gas is 0% ethanol, and I've been getting 2-3 MPG better, so I might start seeking E0 out more.

[Molandfreak]

Why don't you just make a thread and call it "My questions" then you can ask them all in one space instead of making 10 new threads...
BigMatt

That's just mean, man! These are all great questions!



Ditto Stalin. Each quik trip does everything great, from banana bread to gas!

[realjd]

My car requires premium. The owners manual says if premium is not available, put in no more than half a tank of regular and drive slowly (<50mph) to the nearest gas station that offers premium and fill it up the rest of the way. There's also a big "premium fuel only" placard on the inside of the fuel door.

[tchafe1978]

I always use whichever grade is cheapest, so it's usually 87 or 89 octane in my van. I've never noticed enough difference in engine performance or mileage to make it worth spending the extra money on premium. Everything I've read says that premium is a waste of money, unless your owner's manual specifically calls for it.

My wife's van is capable of running on E85, but the few times I've used E85 in it, I did notice a big drop in mileage, so even tough it's typically 20-30 cents cheaper than regular, I don't put E85 in. There is a station nearby that is run by an ethanol producer, and they sell regular (E10), E25, and E85. We will put the E25 in if we are in that town, as it is usally 10-15 cents cheaper than regular, and I don't notice as big of a srop-off is mileage as with E85. I find the E25 to be like a compromise between the higher price of regular and the lower mileage of E85.

[SSOWorld]

Mid-grade in Iowa and surrounding counties, regular elsewhere.

[Takumi]

93 in both cars due to age.

[InterstateNG]

Why don't you just make a thread and call it "My questions" then you can ask them all in one space instead of making 10 new threads...
BigMatt

This.

[NE2]

Why don't you just make a thread and call it "My questions" then you can ask them all in one space instead of making 10 new threads...

You make dumb threads too, sheephater.

Anyway, I use the kind with no vaseline.

[kphoger]

Mid-grade in Iowa and surrounding counties, regular elsewhere.

Same here.  I've never owned a car that didn't call for Regular, so that's what I put in the tank.  But, in Iowa, the mid-grade with ethanol is cheaper, so I put that in when I fill up in Iowa.  In México, I get Magna.

[Dr Frankenstein]

Regular 87, mostly because I'm cheap, and gas is very expensive where I live.

[StogieGuy7]

There's a Quik Trip about 3/4 of a mile from my pad that sells E0 (ethanol free) gas.  I can't remember if it's 87 or 89 octane.  It's about 12 cents more a gallon than the E10 but my car runs better on it and it gets better mileage.

I haven't seen a place with E0, but would sure be delighted if I did!  I live near the IL/WI border and usually gas up in WI because it's 20 cents cheaper.  That said, it's E10 everywhere here.  And there are many stations offering E85, though none of my vehicles have the flexfuel capability.

On this note, I have one vehicle that requires premium.  Aside from Speedway, every other brand has recently priced premium at 40 cents higher per gallon than regular.  Speedway is still 20 cents. 

I hope that this is just a short-term regional thing and not a trend because it is absurd.

[agentsteel53]

every other brand has recently priced premium at 40 cents higher per gallon than regular.

I think that probably makes sense, given that the "10 cents between grades" principle has been around since gas was under $2!  I remember 1.43/1.53/1.63, for example, at my corner gas station in 2003. 

so now that the gas price has doubled, the difference in price between grades should probably double too.

[Truvelo]

I've used the cheapest grade in all the rental cars I've driven in North America. If they require premium than any damage to the engine won't manifest itself until well after I've returned the vehicle

[empirestate]

I use regular (87) exclusively, since I don't have a car that requires anything higher. Strictly speaking, the only reason to buy anything higher is if your engine is knocking at the lower octane ratings. If it is, it's because your fuel is igniting prematurely due to compression, before the proper time when the spark plug is supposed to set it off. Higher octane ratings increase the amount of compression the fuel can reach before self-igniting, thereby increasing the likelihood that the spark will do the job before that threshold is reached.

Elevation can make a difference, since atmospheric pressure is lower at higher altitudes. If my logic is correct, this means you can use a lower octane at high elevations than your engine might normally require. I suppose this also explains why it's often in the mountainous western states where you tend to find lower ratings like 85 or 86.

It also wouldn't be surprising if fuel companies were putting additives into their higher grade fuels, to boost sales from drivers who don't otherwise need those grades. But in general, terms like "premium" and "ultra" are misleading as they apply to different octane numbers, since there's no more difference in quality than there is between a pair of jeans that's in your size and a pair that isn't.

If you do prefer higher grades because of additives, then it probably makes sense to get the highest grade, since the mid-grade fuels are often simply a mix of the highest and lowest ones sent to the same nozzle, so whatever additives there are would be diluted. You may also be able to buy the additives separately and save money, depending where gas prices are. But as several here have pointed out, if you see no difference in performance, go with the cheaper option.

[CNGL-Leudimin]

Types of gasoline
87 octane: regular
89 octane: middle-grade
91 octane: premium
93 octane: ultra-premium

How about 95 octane and 98 octane? . Well, actually the 95 octane gasoline from here is like the U.S. 91 octane and the 98 octane is like the 93 octane one. The 92 octane gasoline, which was equivalent to 87 octane one, hasn't been sold for decades.

Oh, and I use the premium gasoline. As I said, we only have premium and ultra-premium.

[Duke87]

How about 95 octane and 98 octane? . Well, actually the 95 octane gasoline from here is like the U.S. 91 octane and the 98 octane is like the 93 octane one. The 92 octane gasoline, which was equivalent to 87 octane one, hasn't been sold for decades.

Gas in Europe is the same octane-wise as gas in the US, it's just that the method for calculating it is different, which means the numbers are slightly different.

My car takes regular (87), so that's what I put in it.

A friend of mine has a Smart Car. The supposed benefit of it is that it's good on gas. And it is... but it requires premium (93), which basically negates the savings.

[bugo]

I saw a Smart car pulling a small enclosed trailer last night.  My friend and I laughed for a good 5 minutes.  I mean what's the point? Just buy a real car with a trunk.

[empirestate]

I saw a Smart car pulling a small enclosed trailer last night.  My friend and I laughed for a good 5 minutes.  I mean what's the point? Just buy a real car with a trunk.

If your neighborhood had parking like mine does, you'd see the point. :-)

[realjd]

How about 95 octane and 98 octane? . Well, actually the 95 octane gasoline from here is like the U.S. 91 octane and the 98 octane is like the 93 octane one. The 92 octane gasoline, which was equivalent to 87 octane one, hasn't been sold for decades.

Gas in Europe is the same octane-wise as gas in the US, it's just that the method for calculating it is different, which means the numbers are slightly different.

My car takes regular (87), so that's what I put in it.

A friend of mine has a Smart Car. The supposed benefit of it is that it's good on gas. And it is... but it requires premium (93), which basically negates the savings.

Does it negate the savings? A 10 gallon fill up of premium vs regular is $4, assuming premium costs 40c more than regular. A high MPG car easily can make up that cost difference. Of course Smart cars get mid-30s in gas mileage which isn't really that great for a supposedly efficient car...