I just bought a 2008 3.2L A6, the manual said use 87 octane gas but use 91 octane for performance. What is everyone here using for octane and if there is a noticable difference in power and MPG between the 2 octane.

thank You

 

Octane ratings requirements are result of climate conditions as well:
elevation, temperature, humidity.

Do some research on the web, you will get plenty of info that will help for basic understanding.

 

Yes I know that octane ratings requirements depends on elevation, temperature, humidity. But say if all these parameter were in the normal range, is there a noticable difference in using 91 octane in the 3.2 A6 as opposed to using 87 octane.

 

STF. This has been discussed. Since I have a 4.2 I can't help you with the 3.2

 

Go with the higher octane. I did notice a difference when I ran a tankful of 87. Right now I pay about 20 cents per gallon more for 93 octane which comes out to about $120 per year. Pretty cheap price for the added performance.

 

chapchuk, did you notice better gas mileage as well. Sometimes that can offset the cost of the premium.

 

I have a 2.8 and I can tell a diffeence in MPG and performance. My dad has a touareg with the 4.2, he ran regular in it once, both were reduced. We both always run premium (92 oct).

 

higher octane fuel will give u better gas mileage and performance bc it burns cleaner then lower octane fuel....also it reduces engine sludge build up from burning cleaner

 

You mean carbon build up right? As far as I know, all the gas brand uses the same amount of detergent in their regular gas and premium gas, with the exception of Shell and few other brands. I usually use Techron once a year anyways, so carbon build up is not a big concern. Its just that many cars merely recommands 91 octance like the 08 A6 V6, it does not require it. Some car can take full advantage of the higher octance and some does not. If the 08 A6 V6 can take advantage of the higher octane in a way that increase power and fuel efficiency, then its well worth it.

 

your car will pay you back in longevity by using premium.