I have had the Triple Dog for 3 years now. Use it on '04. 5, 5. 9 3500. I like it because it is a programmer, not an add on chip. Very easy to install and uninstall. Has 3 settings giving up to 100? hp and 140? ft/lb torque in extreme mode. You will think you have a completely different truck in extreme! However, I did not see any increase in MPG. But it does make the engine run much smoother than stock. As previously said, it can be used with dodge, ford or chevy. I believe the "try before you buy" is the extreme version, but you can call Bully Dog tech support and get info from them if you have any questions during your trial.