and the reason they have a 91 0ct and 93 oct is because some areas dont have 93 octane, it will never hurt you to put in 93 if you got chipped for 91, FYI

 

GIAC doesn't make a 93 Octane chip.

APR makes both 91 and 93 Octane.

 

David- why then would they as if I use 91 or 93 on the form?

THx guys,
A4

 

Either way 91 or 93 is fine its not a terrible difference between them its not like your car is going to completely **** up if you go with a higher octane its probably programed for 91 seeing how giac doesnt offer a 93 oct program but you might see a better range in gas mileage if you go with 93 consistantly. I had giac on my other audi running pc16 and i ran 93-94 and it ran great.... till it got stolen.

 

its not going to knock on 91 octane

 

wow man you don't own a race car....... damn

the difference between 91 and 93 doesn't matter at alllllllllllllllllllllllllllllllllllllllll!!!!!!!

 

Woohoo! Another convert to the side of logic and reason.

Also, especially in winter, the difference between 91 and 93 won't hurt your car. Get 93 to be safe, since, as the immutable logic of math tells us, it's a lot lot cheaper than a new engine, but you shouldn't worry. Over time, higher octane than optimal will clog your cat, ruin your O2 sensor, etc etc, since the higher octane can't be used, and is just turning into unburnt buildup. Lower octane will cause you to "ping" or detonate when combustion temps get high, and your ECU will adapt to it, but it's needless power loss. Just call who chipped you and ask.