After begining to modify my MCS with the bolts ons such as intake, exhaust, pulley, etc. I began to notice that my gas mileage seemed to increase. I am getting ready to put in an RMW cam and was wondering what this may do to the gas mileage. I was also curious to see what others got with their upgrades...

 

Most performance parts increase performance by increasing efficiency. Thus when you aren't slamming it, you will notice an increase in mpg. But this is irrelavant to some - they get better mpg driving the MINI like a lunatic than most others get driving different cars like a granny.