In Reply to: Down side to chipping a 525i??? posted by GEETEELEE on April 02, 1999 at 09:42:05:
I don't know if this helps cuz I have a 5 spd but I coupled the Conforti chip with a K&N filtercharger. I was immediately impressed with the HP gain and my MPG went up 2mpg. Because you have to use 93 octane, this may be why I got the MPG gain. Anyway, I was glad I got the 2.5 liter instead of the 3.5 after this upgrade. I get 25-27 mpg while you'd be lucky to get 19 in the 3.5. My next move is to get an exhaust.
Also, there may be a transmission chip for your vehicle too. Not sure.