Think about it . with a intake and exhaust system you should get better gas mileage, better overall air flow less restriction. I have a Calmini exhaust I notice a little incerase when I got it on, I also notice that it dose not recoil as much when I let off the gas at high RMP's to switch gears . I have just recived my K&N cone filter and that should make the X preform better still I hope, dont talk my word for it check out the review I think there is gas mileage stats there to . Later Man