hi, i have an 02' cooper s with a typhoon CAI, MSD coil packs, plasma booster, iridium plugs and 8mm wires. I just installed a borla street exhaust about a week ago and since then i have lost MPG(about 20-21 avg). I drive "spirited" as some would call, with minor rallying on the weekend . Other wise i drive pretty normal with about a 50/50 ratio of freeway(going about 70-75) and main road(going about 40). I have flushed my engine and injection system with "Z-max" engine cleaner( suggested by my buddy at kraigen auto parts). I was wondering if any one has had the same problem or if any one has any ideas how to mend this problem( seeing that gas is reaching about 4 bucks a gallon ). Thanks for the help and happy motoring!

 

More than likely its due to the fact that, like many others, when you get a new exhaust you tend to rev up a little higher before shifting and give her a little more throttle than usual.

Jack

 

you know what, ive noticed that thats a problem with me. i just cant stand not rolling down the windows and just giving it hell. thanks alot for the input

 

yup,it probably has more to do with your right foot than anything else