I just bought an a 2000 A6 2.7T Quattro Tiptronic. Can I use regular, or even midgrade, even though Audi recommends Premium? The first time I filled it up I used premium even though two salespeople told me that (one said regular, one said "at least midgrade") would be fine, just that I should "fill it with premium every third tank to clean it out"- they clearly had no idea what they were talking about. So has anyone experienced performance decreases or knocking using less than premium? Hell, am I the only sucker that actually used premium?

Thanks a lot, first post btw.

 

No dice use preimum dude unless you are leasing or u just don't care about ur car you are running a biturbo system and it will run like garbage on 87 I only have a 1.8T and I am running sunoco 94

 

Use premium only. The mod will know if you don't
Seriously, you should use the best gasoline for your car Gas stations that have >91 are too far away for me, so i go to QT and use premium. Dont be cheap, spend $40 to fill the tank up!

 

I dont understand... I thought that the only difference between 87 and 91 octane was that 91 takes more energy to ignite... they both are supposed to have adequate cleaning additives, similar purity, etc. I understand that knocking is bad for an engine... but if I could use regular gas without knocking, I dont understand why I would have a problem.

 

Actually, 91+ octane gasoline burns slower than lower octane. What causes detonation (knocking) is the lower octane builds too much heat in the combustion chamber and causes hot spots that ignite the fuel/air mixture before the spark plug is cycled. Detonation is VERY BAD for your engine....some damage that can occure is broken spark plug electrodes that then can bend valves, scar cylinder walls ect.

I know it hurts the wallet, I am on my third turbo car (all use premium), but the extra 10 cents a gallon is worth it.

Andy