Well after I got the URD MAF Cal. I noticed I went from 17 MPH to 12.5 MPH! I have not had it tuned but I thought the MAF along with the CAI, Gaylord Tonneau, headers and Exhaust were supposed to raise it a few MPH or at least stay the same? After my Tune if I don't get at least the same MPH as stock I removing that MAF Cal. and throwing it the trash!