The owners manuel tells me to use high octane in my 97 A6 2.8. What happens if I use cheap gas, will there be a big difference in performance?[]

 

DO NOT PUT 87 IN! If you are going to cheap out on gas at least get mid-grade 89. But the change you are saving each tank by not putting premium in is just pennies compared to what you can spend to pay if you jack up something in your engine. And yes there will be a performance hit because your engine will be knocking, after all there is a reason they tell you to put nothing less than 91 in, because it is engineered for higher grade gas. Why risk it?

 

I run 89 right now and is it worth it still to move to higher?It only goes up $.10 per grade (unleaded mid and premium) where I usually fill up. Just wondering if the added performance of 93 is still worth it over 89.

 

10 cents a gallon, 15 galons = $1.50 per tank.

BOO HOO.

You did afterall decide to buy a German Luxary Car, if you wanted to save money on gas you should have bought a Honda.

 

Re-read your owners manual, if your 2.8 is the same as my 00 2.8 the manual says you can use 87.

edit: I should have read your post more clearly. Yes it will affect your performance. I run 87 or 92, costco doesn't sell 89 so I generally get the 92. The car performs better with the 92. Although 92 is excessive.

 

i do notice a difference in 89 to 92, 89 has a little bit of lag while 92 burns better and has better acceleration, even at 82.5k

 

If you check your fuel economy (mileage) with 87 vs. 91 or 92 you will generally find the higher octanes give you better mileage, thus the cost is a wash and in many cases you find it is actually cheaper to run the higher octane.

In my case, if I run 89 I average about 18-19mpg highway (I have only done this once when 91 wasn't available at the station, so this is by no means a scientific study). Upgrading that to 91 I can consistently get 26mpg. That is a 40% difference in fuel economy, and considering the cost difference is only about 3 or 4% it makes sense to continue to do so.

Plus, the engine has to de-tune itself when it runs on a lower octane which means higher chance of knocking (you can't always hear knocking, but it is happening) and lower overall performance. I just don't see why you would risk it when the cost difference is so minimal. I wouldn't even put 87 octane fuel in my lawnmower.

 

93 only. It keeps your engine cleaner, it's more efficient, both in fuel consumption and performance. And keep in mind... You're driving an Audi. Audi is a german luxury vehicle, not a honda civic beater. Sorry to sound harsh but really for only $1.50 a tank extra, its ridiculous to even think about 87. I would also HIGHLY recommend checking out www.toptiergas.com , they provide you with a list of the highest quality fuel providers, and for those still somehow skeptical... reasons why you should use a top tier fuel. Man I hope thats the end of these 87 questions lol.

 

It takes me $60 every week to fill up on 93 at $3.03, I paid as high as $3.69 at one point. Dont be cheap on your gas, just drive less and make that 93 last longer. The Sunoco's in Maryland use to sell94, not anymore tho. You could really tell the difference grades, I miss that 94[sm=smiley19.gif]

 

Damn, yeah I have heard of the Sunoco 94 before. That's soooo gay I can't even find 93 around here....[>:]