So far Ive added a K&N FIPK and a Magnaflow cat back. It sounds great but ive only gained about .5 mpg. Im getting 15 - 15.5 in mixed driving and hwy mileage I get 17mpg at 70 mph. My next step is a Hypertech programer but Im not sure which to go with either max energy or the e con. I was doing some reading on the Jet MAF and they claim an increase in mpg but dont say how much. I'm curious if any of you have one and what kind of gain you got if any. Is there anything else I can do to get an increase in mpg? Im a light footed driver, tires are properly inflated and I use royal purple.