Bully Dog 40420 Triple Dog GT Platinum Diesel Downloader

1999-2015 7.3L/6.0L/6.4L/6.7L Powerstroke | 2001-2015 6.6L Duramax | 2003-2017 5.9L/6.7L Cummins*
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Bully Dog Technologies
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The Bully Dog GT 40420 is a downloader AND a monitor all in one compact electronic device!  Considering all the features contained within the GT it is amazing that installation is as easy as plugging the unit into the OBDII port and performing a simple download to the vehicles ECU. What's more convenient is that the Bully Dog GT 40420 works on almost all late model diesel pickups and even some commercial applications.

The Bully Dog GT 40420 features the all new patent pending Driving Coach feature. According to outside research studies, drivers can save up to 37% on their monthly fuel bill simply by adopting better driving habits. The Driving Coach feature shows people specifically where their current losses are coming from so they can make adjustments to correct their inefficiencies. In doing so, the Coach provides audio and visual feedback to instruct a driver on how to learn better driving habits. Read more about the driving coach feature below.


The 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 particular 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."

Bully Dog GT 40420 Features:
  • Added horsepower and torque
  • Improved fuel economy
  • Safety Defueling
  • On-the-fly power level adjustment
  • Four different power levels to choose from
  • Easy installation (20-40 minutes)
  • Free internet updates and upgrades
  • Monitor and display vehicle parameters (PIDs)
  • Full Color display with multiple color themes
  • User set daytime and night time driving modes
  • Display current gear on vehicles with auto trans.
  • Vehicle specific download features
  • Initiate DPF burnoff on ‘09 GM and Dodge diesel
  • Defuel based on user set safety parameters
  • Read and Erase Diagnostic Trouble Codes
  • Display instant fuel economy and trip fuel economy
  • Exclusive Driving Coach feature, Patent Pending
  • Universal Suction Cup Mount included
  • Holds up to 10 custom tunes (not included)

Performance Gauge Functions:

  • 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
  • Pyrometer #1 & 2 optional (diesel vehicles)
  • Boost (diesel vehicles)
  • IPW: injection pulse Width (diesel vehicles)
  • Barometer (diesel vehicles)
  • Oil temperature (diesel vehicles)
  • ICP: injection control pressure (diesel vehicles)

NOTE: 40384 Sensor Station with Pyrometer Probe is required to read EGT's on all non-DPF equipped pre-2007.5-2008 models. (sold separately)

Applications Include: 
  • 1999-2015 F-Series 250-550 7.3L/6.0L/6.4L/6.7L Powerstroke (Excludes 2013+ Cab & Chassis & Manual Xfer Case)
  • 1999-2005 Ford Excursion 7.3L/6.0L Powerstroke
  • 2003-2017 Dodge Ram 2500-5500 5.9L/6.7L Cummins  (2013-2017 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

Bully Dog GT application chart/ vehicle info sheet

Mfg. Number:

Customer Reviews - Include your order number for a chance to win a $100 GiftCard

(1019 Ratings, 34 Reviews) Average Rating:
01 DURAMAX!!!!
Kadin (Eunice NM) 4/19/2016 11:25 PM
Instantly felt more power and gained 2 mpg but been a lil heavy on the pedal. Overall I'm extremely impressed
Pros & Cons
Ruffneck (Texas) 9/3/2015 8:54 PM
Installed this unit on my 04 5.9 and immediately lost 2 MPG calculated manually not with OBC. I have tried multiple tuning combinations and have come close to pre BD mileage, but have never been able to get the mileage I was originally getting without the tuner. with that being said I do like the increase in power/torque that I have seen. Running 75MPH unloaded I average about 18-19 MPG regardless of what mode the tuner is in. Pulling a 24' toy hauler I get about 10-11 MPG running 60 MPH in tow mode. Overall I'm happy though was just expecting a bit better mileage like some others have claimed.
Bully dog GT diesel tuner
Cameron (Oregon ) 5/17/2015 6:59 PM
I bought this thing because all of the claims of great gas mileage increase. I was skeptical because people were claiming 24-32 mpg results in a 7.3 diesel. Well I'm not sure if people are reading the monitor or actually doing the math. Because my monitor says I'm getting 24-29 mpg. But when I do the real math (filling up, driving. Filling up again and dividing the miles. I'm getting 13-15mpg not 24-32 like the tuner says. Other then that the power increase when needed is pretty good. Of course now I get over boost on my turbo, but the power is great. If you want power then get this. If you want to look cool and show your friends that your truck gets high mpg according to your tuner get it. But if you're looking for a real mpg improvement this isn't worth the money.
Great Power & MPG
Chuckr (Roy, WA.) 12/13/2014 5:46 AM
I had my GT tuner installed by a local Auto shop at 1.25Hrs. My 2000 Ford F-350 has many power modifications, and the GT tuner replaced my Banks chip. Prior to this, my best HWY MPG was 20.5, with an all around average of 16-18MPG. When I picked the truck up I noticed two things: 1. I had approximately the same amount of power in Level 3 (Performance) as I did with my Banks chip, and still have another level (Extreme) if needed. 2. My milage computer read 19.6 MPG. As I drove into the mountains (up hill) at 75 MPH, mile milage was increasing! By the time I returned home (250 miles)my milage computer was registering 22.1 MPG and took a little over 1/2 tank (about 20 gallons) of fuel. Very impressed, so far!
2014 Ford F 250 6.7
Keith (Mississippi) 11/27/2014 1:22 AM
I just installed this on my 6.7. It def is a good buy for the price. I have had no problems out of it. Increased mpg by 3.6 mpg. You can really tell it has more HP now. No more turbo lag. Only downfall is it will not work with DPF delete.