The Max Energy? tuning provides additional power and optimized transmission functions, resulting in less fuel to accelerate and maintain cruising speeds without the torque converter unlocking and transmission down-shifting to a lower gear. The results are maximum power and fuel mileage. For gas vehicles that come from the factory capable of using regular octane fuel, two (2) optimized tuning programs are provided: one for premium, and the other for regular. Only one (1) power tuning program is provided for vehicles that were designed from the factory to use only premium fuel. For diesels, the Max Energy? offers three (3) stages of power tuning for diesels. Even the highest power level, Stage 3, maintains safe EGT's while towing the maximum weight specified by the vehicle's manufacturer. Hypertech?s low EGT's, proper transmission shifting, and superior tuning that doesn?t require de-fueling.