Bully Dog GT Platinum Diesel Tuner and Gauge

$549.00 $449.00

The Bully Dog GT 40420 is a performance tuner AND monitor all in one compact electronic device! Get more horsepower, torque, and increase fuel efficiency in your truck with Bully Dog’s legendary tuning. All you need to do is plug the GT Tuner into your OBDII Port and perform a simple download to the vehicles ECU.

With industry leading features such as on-the-fly power level adjustments, safety defueling, and the exclusive Driving Coach, the GT Tuner is the premiere all-in-one tuner. The GT Tuner gives you multiple power levels so you can maximize the power and efficiency of your truck whether you’re towing, daily driving, or on the track! The GT Tuner features a full color display with multiple themes and has a day and night time driving mode, so you can always quickly and clearly monitor important vehicle parameters. In addition, the GT Tuner can be used as a diagnostic tool giving you the ability to read and clear diagnostic trouble codes. 
Bully Dog Driving Coach 
Driving Coach is a special feature designed to help drivers drive more efficiently. It coaches drivers into better driving habits by providing real time visual and audio feedback as to how efficient a driver is driving. The driving coach also provides the driver with a "grade," on how efficiently they drove during a trip. This makes driving efficiently, constructive, and fun! Drivers can use the Driving Coach to coach themselves into improved driving habits. Every driver can challenge themselves to be "The perfect driver."

Parameters Monitored With Performance Gauge Function:
Real Time Fuel economy, Average Fuel economy, Trip Fuel economy, Load %, Coolant temperature, Fuel rail pressure (diesel vehicles), Manifold absolute pressure, Engine RPM, Speed, Timing position, Air intake temperature, Mass Air Flow (grams/sec.), Throttle position, Fuel level, Battery voltage, Ambient air temperature, Transmission temperature. Along with the following diesel specific parameters: Pyrometer #1 & 2 (optional, probe sold separately), Boost, injection pulse Width, Barometer, Oil temperature, injection control pressure

  • Increases Horsepower & Torque
  • Exclusive Driving Coach Feature 
  • All-In-One Gauge Display & Tuner
  • Universal Mounting Suction Cup Included 
  • Reads & Clears Diagnostic Trouble Codes  
  • Defueling Based On Set Safety Parameters 
  • Initiates DPF Burnoff (Most 2009+ GM / Dodge Models) 
  • Free Internet Updates 

Applications Include: 
1999-2019 F-Series 250-550 7.3L/6.0L/6.4L/6.7L Power Stroke (Excludes 2013+ Cab & Chassis & Manual Xfer Case)
1999-2005 Ford Excursion 7.3L/6.0L Power Stroke
2003-2021 Dodge Ram 2500-5500 5.9L/6.7L Cummins  (2013-2021 models require 42214 Unlock Cable, online update may be required for 2016 models.)
2001-2015 GM 2500/3500HD 6.6L Duramax
2006-2010 GM Kodiak/Topkick 4500/5500 6.6L Duramax
2006-2014 GM Savannah/Express 2500/3500 6.6L Duramax

Optional EGT Probes sold separately. See items below. 
2018-2021 Ram 6.7L Cummins models require the Bully Dog 42215 GT Bypass Cable Kit. See Related Items Below
2013-2017 Ram 6.7L Cummins models require the Bully Dog 42214 Unlock Cable, online update may be required for 2016 models. See Related Items Below

Performance Gains

Bully Dog GT application chart vehicle info sheet

Bully Dog 40420 Performance Gains chart


2001 Chevy 6.6L LB7 Duramax
2002 Chevy 6.6L LB7 Duramax
2003 Chevy 6.6L LB7 Duramax
2004 Chevy 6.6L LB7 Duramax
2004.5 Chevy 6.6L LLY Duramax
2005 Chevy 6.6L LLY Duramax
2006 Chevy 6.6L LLY/LBZ Duramax
2007 Chevy 6.6L LLY/LBZ Duramax
2007.5 Chevy 6.6L LMM Duramax
2008 Chevy 6.6L LMM Duramax
2009 Chevy 6.6L LMM Duramax
2010 Chevy 6.6L LMM Duramax
2011 Chevy 6.6L LML Duramax
2012 Chevy 6.6L LML Duramax
2013 Chevy 6.6L LML Duramax
2014 Chevy 6.6L LML Duramax
2015 Chevy 6.6L LML Duramax
2003 Dodge 5.9L 24V Cummins
2004 Dodge 5.9L 24V Cummins
2004.5 Dodge 5.9L 24V Cummins
2005 Dodge 5.9L 24V Cummins
2006 Dodge 5.9L 24V Cummins
2007 Dodge 5.9L 24V Cummins
2007.5 Dodge 6.7L 24V Cummins
2008 Dodge 6.7L 24V Cummins
2009 Dodge 6.7L 24V Cummins
1999 Ford 7.3L Power Stroke
2000 Ford 7.3L Power Stroke
2001 Ford 7.3L Power Stroke
2002 Ford 7.3L Power Stroke
2003 Ford 6.0L Power Stroke
2003 Ford 7.3L Power Stroke
2004 Ford 6.0L Power Stroke
2005 Ford 6.0L Power Stroke
2006 Ford 6.0L Power Stroke
2007 Ford 6.0L Power Stroke
2008 Ford 6.4L Power Stroke
2009 Ford 6.4L Power Stroke
2010 Ford 6.4L Power Stroke
2011 Ford 6.7L Power Stroke
2012 Ford 6.7L Power Stroke
2013 Ford 6.7L Power Stroke
2014 Ford 6.7L Power Stroke
2015 Ford 6.7L Power Stroke
2016 Ford 6.7L Power Stroke
2017 Ford 6.7L Power Stroke
2018 Ford 6.7L Power Stroke
2019 Ford 6.7L Power Stroke
2001 GMC 6.6L LB7 Duramax
2002 GMC 6.6L LB7 Duramax
2003 GMC 6.6L LB7 Duramax
2004 GMC 6.6L LB7 Duramax
2004.5 GMC 6.6L LLY Duramax
2005 GMC 6.6L LLY Duramax
2006 GMC 6.6L LLY/LBZ Duramax
2007 GMC 6.6L LLY/LBZ Duramax
2007.5 GMC 6.6L LMM Duramax
2008 GMC 6.6L LMM Duramax
2009 GMC 6.6L LMM Duramax
2010 GMC 6.6L LMM Duramax
2011 GMC 6.6L LML Duramax
2012 GMC 6.6L LML Duramax
2013 GMC 6.6L LML Duramax
2014 GMC 6.6L LML Duramax
2015 GMC 6.6L LML Duramax
2010 Ram 6.7L 24V Cummins
2011 Ram 6.7L 24V Cummins
2012 Ram 6.7L 24V Cummins
2013 Ram 6.7L 24V Cummins
2014 Ram 6.7L 24V Cummins
2015 Ram 6.7L 24V Cummins
2016 Ram 6.7L 24V Cummins
2017 Ram 6.7L 24V Cummins
2018 Ram 6.7L 24V Cummins
2019 Ram 6.7L 24V Cummins
2020 Ram 6.7L 24V Cummins
2021 Ram 6.7L 24V Cummins