how does adding 91 octane effect gas mileage?
 

my local gas station only offer 89 and 91 octane and I understand that the higher octane, the more "pure" the gas is. But often times I drive 8 miles or so to get a 93 octane, it is good for the drive train, but I have been lazy and stay with a 91. The question is that

1) are there any gas mileage differences adding a 91 as opposed to 93? I heard that if you use 93, the engine would have a higher gas to power ratio, thus effecting the mileage.

2) would using 91 hurt my engine/car in the long run? I think there are some addictives that you can use to clean the valve..etc

thanks for your attention.

i usually use 91, i've used 93 once or twice
 

haven't really noticed a difference

91 gas is fine (that's all we have here in CA)
 

93 is only really worth it if you have a chip and programming is tuned for 93. You don't really want to go below 91 because your stock car will automatically retard the engine and you'll ending up getting both less power and lower fuel efficiency. With 93 it will advance slightly, but w/o a chip the gains are minimal and will most likely be unnoticeable.

what's with your sig? 8.1T?

i'd love to have an 8.1T

haha, I switched the badge 8 and 1 around...

your A4 some kinda viper fighter?
 

that be one big freakin four banger ;-)

yup pretending to be... mod mod money!

haha...can ya spare a lil
 

i'm a little short in the mod fund right now ;-)

lol