the mp-8 is pretty sweet. its an easy install and it def. has a power boost. i dont see much benefit other than jacking up fuel rail pressure, but let me tell you, before my turbo spools up to 45ish ill roll some serious coal . as for mileage increase, i dont really see much. my overhead says 24-26 on the highway, but when hand calculated (this is from a cross country drive) its still holding solid around 19.5 at 2200rpm and 75mph. stock 32.5s and rear. i will warn you if you have the 68rfe, you might wanna upgrade it because it doesnt handle much more than stock hp....