This is the best diesel tuner on the market. It gives up to 90 HP gain, better throttle response, and better fuel mileage without bypassing, deleting, or defeating any emission control systems. Adjustable knob for 0,30,60, or 90 HP can be run into cab or left under hood. 15 minute install. I sold my truck that I used it with. They sell for $450. I will sell or trade for gun stuff.