Parts & Accessories Car inspection services The Bully Dog GT Gas Performance Tuner and Monitor enhances fuel economy (40417) unlocks more horsepower and torque to meet the unique demands you place on your vehicle. With pre-loaded tuning, you can simply plug and play. Customizable gauges track performance for a wide range of hauling and off-road applications, providing significant power for tough jobs or improving fuel economy for long highway cruises. The all-in-one display and monitor provide a full-color display with customization, vehicle-specific download features, and the ability to read and clear diagnostic trouble codes.