Premium Fuel Required?

[photon]

Yeah that's the one I used to go to all the time, the one on Elbow and 96th or so.

[Ironhorse]

Originally Posted by Sylvanfan

Well from what I understand the higher the octane level the cooler the engines burning temperature.

Not quite:

Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders.

http://autorepair.about.com/od/engin...hoctanegas.htm

Many high-performance engines are designed to operate with a high maximum compression and thus need a high quality (high energy) fuel usually associated with high octane numbers and thus demand high-octane premium gasoline.

http://en.wikipedia.org/wiki/Octane_rating

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel.

http://auto.howstuffworks.com/question90.htm

Originally Posted by Sylvanfan

Well from what I understand the higher the octane level the cooler the engines burning temperature. So if your vehichle is reccomended to use regular, than use regular fuel becuase your engine will operate at the temperature that it's designed to get optimal perfomance.

Conversely if you put the regular in a vehichle that requires 91 octane fuel, you're engine isn't going to get peak perfomance and operate at it's maximum efficiency.

Didn't they tweak the V6 in the Toureg to get it up to like 245 horse for 07. I was looking at Toureg's earlier, but could only afford a used one. I didn't like the power of the old V6 and the V8 was just going to be too expensive to run.

Yes, the 2007 Touareg has a new V6 but they actually tweaked it to 280 HP. It is the old engine that had 245. The new V8 is a beast but as an $8000 option its a little pricey, not to mention thirsty.

[ken0042]

Originally Posted by hulkrogan

If I recall you drive a Grand Am, which only requires 87 octane. Putting anything above 87 actually slows your car down and decreases fuel economy.

Well, I don't know what the difference is but when I put mid-grade into my tank I get a little bit better city mileage (27 mpg instead of 26) but on the highway I find there's almost 3 mpg difference. (43 instead of 40)

Maybe because I have the V6 in there?

[photon]

BTW, nice car!

[Bill Bumface]

Originally Posted by Ironhorse

Not quite:

Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders.

http://autorepair.about.com/od/engin...hoctanegas.htm

Many high-performance engines are designed to operate with a high maximum compression and thus need a high quality (high energy) fuel usually associated with high octane numbers and thus demand high-octane premium gasoline.

http://en.wikipedia.org/wiki/Octane_rating

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel.

http://auto.howstuffworks.com/question90.htm

Pretty much the same thing. Higher compression means higher cylinder temperatures.

[jolinar of malkshor]

What does BTW mean?

[Dion]

Originally Posted by jolinar of malkshor

What does BTW mean?

By the way.

[Bill Bumface]

Originally Posted by ken0042

Well, I don't know what the difference is but when I put mid-grade into my tank I get a little bit better city mileage (27 mpg instead of 26) but on the highway I find there's almost 3 mpg difference. (43 instead of 40)

Maybe because I have the V6 in there?

Its just the way you are driving, or the weather. Mileage can vary a lot tank to tank with the same gas even making the same trip over and over.

High octane fuel shouldn't be used in cars that recommend 87 because their cylinder temperatures don't always reach the optimum temperature for burning higher octane fuels. You can get incomplete burning which means gas coming out your tail pipe, and a bunch of crap being left in your engine from a dirty burn.

Also, per volume, high octane gas has less energy than low octane gas. So even if it is burning properly in your car there is no way it gives better gas mileage.

[Josh]

As its been stated, octane has to do resistent the fuel is to detonating early.

For those of you who have older cars that require 87 octane, you're just ****ing your money away putting in anything better.

There is a common myth among car owners that you are giving your engine a "treat" when you put in a higher octane fuel. This is simply not the case.

Stick with the manufacturer's recommendation, everyone told me when I got my BMW that I had to put in premium fuel, but when I opened up the gas door it said "89 octane" so that's what I fill it with.

This summer when I was up in canada I filled up at a petro canada and couldn't believe the deceptive marketing used to get you guys to fill your cars with premium. They claimed you would have better emissions etc. That's a crock of ****, if anything using a higher than recommended octane would probably worsen emmission as it takes longer to burn.

[Vulcan]

I'd like to also weigh in on the side of following the manufactures recomendations.
I have a motorcycle with 11:6:1 compression, under 800cc and rated at 108 Hp. Sounds high performance to me and yet Honda recommends regular gas. I only use regular and riders who mistakenly use higher octane report poorer gas mileage and performance. Save your money.

[Sylvanfan]

In all honesty...Mid grade gasoline with 89 octane is useless. Very few people designs an engine to run on 89 octane gas. In Calgary it's only somewhat usefull if you have an engine needing 91 octane because you can use the 89 to get the cylinder temperature up to draw more oxygen out of the thin air.

edit, because evidently BMW's reccommend it. Never knew that.

[Josh]

Depends on the model of BMW. Any ///M car will require premium gasoline but I know for the regular 3 at least the model I have (328), it says 89 octane required.