Most of the "basic" performance mods...pippes, intake(filter/snork) jets (to a point) should actually INCREASE your milage...you are letting the engine breathe easier...this should help by making it so it doesn't have to work as hard...but you get to a point where the returns start to diminish (mileage wise) and you start to eat more fule...with the set up I have I have found my mileage is MUCH better...On the trip to the NorthEast I put in FAR LESS fule than Dill did at each stop...same terrain, speed, and so on...but then I do have that 18 tooth front sprocket...but I had it before some of the other mods and my milage is better still...and we're not talking about a 1/4 gal difference between dills ride and mine....we're talking about more than a gallon diff.
