Sorry,
Haven't figured TDR website out yet... I have a 2006 mega cab with a 6 speed (G-56). I know for a fact the Bully dog resets you iginition cycles, and that is one of the first thing that the dealer checks for. As far as i know the Smarty is harder to detect, but, nothing is for sure. As for mileage increase i normally see about 1-2 MPG with these boxes. nothing to write home about, but better. Of course, the power is awesome.