Originally Posted by A4AvantWgn

That would be true...thank you

Originally Posted by A4AvantWgn

No...but interesting that you would ask..are they that difficult to come by (this is our first Audi...S-line edition)? I still have my eye on the new All-Road

Originally Posted by B5 Fanboy

On average it's about 10 cents more for 91. (in my area at least). With 91 you will gain around 3-4mpg. We will use 3mpg as the base.

Gas is 4.00 for 87, 4.10 for 91. You buy 30 dollars worth.

87: 7.5 gallons
91: 7.31 gallons.

We are going to assume you average 25mpg on 87, and 28mpg on 91.

So, you have the following distances traveled.

87: 187.5 miles
91: 204.68 miles

see the difference?



Now, since some areas have different gas prices, I will use the same formula but with a 20cent increase for 91 fuel. Just to be on the safe side of things.

You have $30 to spend on gas.
87 = 4.00
91 = 4.20

87: 7.5 gallons
91: 7.14 gallons

Same 25 mpg base for the 87 fuel, 28mpg base for the 91 fuel.

87: 187.5 miles
91: 199.99 miles



So, with this said you should use the recommended 91 fuel in your car. It will also burn cleaner and build up less carbon in your engine.

Hope this helped. Please use the correct fuel!

Originally Posted by CMac019

Best comparison I've ever seen!