From my own experience, a programmer did not help with gas mileage. A tonneau cover may be more beneficial to you. What are you averaging? I average about 15 - 15.5 with a Nismo CAI, tonneau and Bullet muffler (if that really helps at all?) I try to keep it under 2,000 RPMs, but I can have a heavy foot at times. I don't think I will get any better than that...unless the gas stations I go to are still on the crappy winter blend.my main goal: better gas mileage. I can get a aem cai and hypertech programmer for 550. will this help my mileage that much? Or at least one more so than the other to get first? i dont have a heavy foot so i wont be driving like i stole it. Would an K&N air filter be just as beneficial? anything will help guys.