The Bully Dog Triple Dog GT Platinum 40420 is an in-cab tuner, gauge, and code reader for select Powerstroke, Duramax, and Cummins trucks. It plugs into the OBD-II port, loads a Bully Dog calibration, and stays on the dash.

The named levels are stock, tow, performance, and extreme. Typical gains are about 50 hp on tow, 75 hp on performance, and 100 hp or more on extreme. A 2015 6.7 is lower, about 71 hp on the top file. A 2017–2019 6.7 is about 131 hp and 210 lb-ft. Not every truck gets every level, and not every truck can change power on the fly. It reads and clears codes, shows more than 15 parameters, and has a driving-coach display. A pyrometer is separate. Custom files for larger injectors or a turbo come from a Bully Dog dealer, not in the box.

It does not delete emissions equipment, and it will not run a deleted truck. It is not legal for sale or use in California. A 2018–2021 Ram 6.7 needs the 42215 bypass cable, which stays installed. A 2013–2017 Ram needs a different unlock cable. Trucks before 2013 do not.

Fitment

• 1999–2015 and 2017–2019 Ford Powerstroke
• 2001–2015 GM 6.6L Duramax
• 2003–2021 Ram 5.9L and 6.7L Cummins
• 2013–2015 cab-and-chassis excluded
• 2018–2021 Ram 6.7 requires cable 42215
• Not for sale in California

Confirm the year in the vehicle selector before you order. Coverage is not every truck in those families.