I installed the Max Energy Programer on my 2006 Chevy P/U - I have the "B" motor, the 5.3L HO and had already installed an S&B cold air box, Jegs Mass air flow sensor, performance single exhaust and 4:10 gears. Installation was a breeze and took aboiut 10 minutes.The truck was already a great performer and the improvement was immediate. I had firmed up the transmission shifts 50%, and set it up for regular gas. Acceleration improvement was crisp, over and above from what the truck already was and shifts were firm but not harsh. Fuel economy went from 17 MPG to 18.9 MPG average at freeway speeds of 65 MPH. Truck is now very much on steroids and is a real sleeper!