Bully dog International GT Diesel Tuner 40428

Bully Dog GT Diesel Tuner

The GT Diesel Tuner unlocks horsepower and torque to meet the demands of towing horse floats, caravans, or 5th wheelers. With shift-on-the-fly tuning*, customizable gauges, and control over de-fueling and regeneration, you’ll have the low-end power for tough jobs or improved fuel economy for long hauls. Store up to 10 custom tunes for all driving conditions.

Dyno-proven tunes deliver increased horsepower and torque.

Vehicle Compatibility

Ford Powerstroke

• 2008–2010 – 6.4L Pickup Trucks & Chassis Cab

• 2011–2016 – 6.7L Pickup Trucks (no Chassis Cab)

• 2017–2019 – 6.7L Pickup Trucks

• F250, F350

Chevy/GM Duramax

• 2007.5–2016 – 6.6L Pickup Trucks & Chassis Cab
  (On-the-fly not available for 2011–2015)

• Silverado

Dodge Cummins

• 2007.5–2009 – 6.7L Pickup Trucks

• 2008–2010 – 6.7L Chassis Cab

• 2010–2012 – 6.7L Pickup Trucks (Chassis Cab 2011–2012 not supported)

• 2013–2017 – 6.7L Pickup Trucks & Chassis Cab

• 2018–2021 – RAM 2500 & RAM 3500 Cummins

40428 - 6.7L Cummins

Tuning               HP        TQ       HP Gain          TQ Gain 
No Power         337      656    
Tow                    400      781           91                     208
Performance  464      906        128                     278
Extreme           473       930        140                    274

40428 - 6.7L Powerstroke

Tune                   HP         TQ       HP Gain         TQ Gain
No Power        339        616    
Towing             363        715          24                     99
Performance 397        751          58                    135
Extreme           421        779         83                    163

1.Switch on the fly between the 4 power levels (Switch- On-The-Fly Not available on Duramax 11-16)

2.No Custom Tuning Custom tuning is not included
3.Product includes Serialized Device (head unit), Packaging, Cables,SD Card (complete ready to sell as per GT Diesel)

Note: 2018+ Cummins require an additional programming cable (available at checkout).

Optional Add-On: EGT Docking Station ($479)

The Bully Dog Sensor Docking Station makes it simple to install aftermarket automotive sensors and display readings on your GT device. Monitor key performance metrics and turn your GT into an engine safety feature while driving.

Adjustable Features & Gauges (Options vary by vehicle model and may not all be available)

• Accessory Delay – Control how long accessories stay on after engine shutoff.

• Auto Door Lock – Automatically locks/unlocks doors at set speeds.

• Boost & Boost Warning – Monitor turbo boost and set safety warnings.

• Coolant Temp & Warning – Track coolant levels and set safety alerts.

• Daytime Running Lights – Enable/disable DRLs.

• Fog Light/High Beam – Use fog lights and high beams simultaneously.

• Head Light Delay – Adjust headlight shutoff delay.

• Horn Chirp Length/On Lock – Customize horn feedback on lock.

• Idle Adjust – Raise idle for powering auxiliary electronics.

• Idle Shutdown Timer – Auto-shutoff engine after set idle time.

• Low End Power – Increase throttle sensitivity across RPMs.

• Mobile Regeneration – Manually initiate DPF regen at highway speeds.

• Oil Temp & Warning – Monitor oil temp with safety alerts.

• Optical Flash on Lock – Flash hazard lights when locking.

• PTO – Adjust PTO RPM manually.

• Pyrometer & Warning – Monitor exhaust gas temps with safety cutoffs.

• Relearn Vehicle Data/Transmission Adaptive Learning – Improves shifting based on driving habits.

• Seat Belt Chime – Disable reminder chime.

• Speed Limiter – Adjust max vehicle speed.

• Stationary Regeneration – Start DPF regen while parked.

• Tire Size – Correct speedometer for non-stock tire sizes.

• TPMS – Modify or disable tire pressure monitoring.

• Transmission Shift Firmness – Adjust automatic transmission shifts.

• Transmission Temp & Warning – Monitor transmission heat and set alerts.

• Unlock Driver Door – Unlock all doors with one press.

Important Information

• For Bully Dog Technical Support, contact: support@bullydog.com. Include vehicle details, issue description, and confirm you are using the Bully Dog International Version.

• This product is for off-road use only. Check if legal in your state or territory before purchase.

• Not for sale in the USA. Orders with U.S. shipping addresses will be cancelled.

✅ More power, better fuel efficiency, full control — the Bully Dog GT Diesel Tuner is built for serious truck owners.