Optimum fuel tuning for awesome power (+127 hp, +345 lb-ft), built-in safety and adjust-on-the-fly power, plus temperature limiting control. Tuning that doesn't kill the host vehicle. Many tuners reduce fuel delivery as exhaust gas temps rise. But they ignore the powertrain! Banks finds the limits of the engine and powertrain, then adds mission-critical ActiveSafety safeguards to Six-Gun so it won't exceed those limits. As a result, Six-Gun thrashes challengers, not your truck! Proof of a higher power. Calibrated for sport applications, Six-Gun is a performance junkie that adds +127 hp/+345 lb-ft. With its comprehensive CleanTune Technology and change-on-the-fly power, Six-Gun rockets you from 0-60 mph 33 percent quicker and in 36 percent less distance than stock - without adding Black smoke! All gains measured at the rear wheels, with recommended airflow improvements. Test Results Chevy/GMC Truck Power Turbo-diesel: 6.6L Duramax LB7, 2001-2004. Test vehicle: 2001 Chevy 3500HD, Extended Cab, Long Bed. Engine: 6.6L Duramax LB7. Transmission: Allison Series 1000 5-speed automatic. Horsepower and torque measured at rear wheels. Note: Banks Horsepower and Torque tests performed with recommended airflow improvements. Upgradeable options include Banks iQ and airflow components to build a complete engineered power system. For best Six-Gun Tuner performance, Banks always recommends airflow improvements.