T

Tried used 87 octane gas in 2.8. Seemingly no problem and cheaper. Should I stick with it?

RickS

Are you saying your A4 isn't worth the extra $1.50 a tank? Your A4 deserves the best!

Audiboy

At least stick with 89. 87 octane is way too easy to burn and if a car was designed to use higher octane due to it's higher compression, then pinging will start to occur using easy to burn gas. You probably don't hear it detonating - unless you really know what detonation sounds like - you have to shut everything other noise sources off such as A/C, radio, etc.., drive in a slight incline, keep it in the same gear - like a higher gear, and listen as you accelerate slowly. Pinging is slight poping sounds, Detonation is what comes after severe pinging - and that's why I won't buy you car unless I am ready to swap engines. Stick with a higher octane. Worst case is you won't fully combust it and the converter will overwork but catalytics are cheaper than an engine - BTW, that's more like using 110+ octane. 92 won't cause the catalytic to overheat.

JETPILOT

The lower the octane you use the better performance you will get. As long as pinging is not a factor. You should use the lowest octane fuel that you don't get pinging (which is one and the same as detonation) with.<p>If 87 does it for you then get 87. Octane is the fuels resistance to combustion. The higher the octane the higher the pressure that fuel can resist before combusting. If the pressure becomes too great for any given octane the fuel will explode violently instead of combusting and expanding at a predictable rate. That's detonation/pinging.<p>

kj

if I were in the middle of the desert and that is all they had, then yes, otherwise NO

ChuckH

...hear it with the windows closed, but can with them open and when you stomp on the throttle. Also, the timing retards quite a bit going up hills, which causes surging. I think the difference in cost is so neglibible anyway, that why not feed it what it likes? On my 90Q I even take it one step further and use supreme + 104+ octane boost to totally eliminate the surging. Kepp in mind that Audi uses high compression engines and advances the timing considerably. Although the computer may retard the timing to reduce pinging, it may not be able to catch it before it actually happens. Even though you may not hear it in the car, don't count on it not being there. Obviously if you don't drive up hills or do full throttle driving, you may not have a problem, but if I were you, I'd soend the extra $2.00 or whatever per tank. :-)<p>Charles<br>

JonathanD

I would stick with the higher grade simply because that's what they say to use. They have things set in the engine to burn that level of octane, although less will work, I wouldn't change from 93.

Brad Bilut

May you should have gotten a VW of you can't afford to gas up your Audi. Just kidding!

tk2x

If it's not pinging, especially if you're not<br>driving it hard, go with 87.

Boink!

nt<br>