Ive tried Bully Dog, Hypertech, Diablosport and a Hyperchip on my 2500 hd. Bully Dog didnt do s#@t besides drain my pocket same went for hyperchip. Diablosport had a increase in mpg, but in the end i went back to the one started with it is the hypertech e-con save me a average of 3 mpg. Deisels i have heard bully dog worked well.