Steven6095

I have to disagree with the milage thing:
Doug's 89 tune gets me much better milage than the 87
but each car and each tune is different

howarmat

I would also think that the 89 you are running is better quality gas which should give better milage. I have always run higher oct gas in my vehicles, they dont seem to run near as well on the lower octane....dont know if its the quality or the octane though. Its usually shell, BP or sunoco.

HEMIstang

I have a K&N FIPK on mine.