Bully Dog GT Platinum Diesel Tuner – 2021 Review

| Last Updated: August 19, 2021

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Diesel operating vehicles are known to cost their owners a lot, especially with the prices racking up regularly. 

If you are a regular user of a diesel-operated truck, you would definitely benefit from installing a tuner on it. And not just any other tuner, but the Bully Dog GT Platinum Diesel Tuner. 

In this article, we will discuss its various aspects, how it will help save you money and protect your car in the long run. Stick around till the end to know all the information about this little piece of technology. 

  • Suitable to be used with a wide range of Ford, Dodge, and GM models
  • this will help to improve fuel economy
  • A clear and easy to use LCD display
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Bully Dog 40420


  • Safer defueling
  • Preloaded tunes
  • Supplied as a complete kit
  • Display has a user-friendly interface
  • Allows you to monitor critical engine data


  • Lacks a touch screen display
  • Technical support is not readily available

Specs and Dimensions

  • Product Dimensions: 6 x 6 x 3.8 inches
  • Fits: GM/Ford/Dodge/Chrysler/Jeep/Nissan/Toyota
  • Extreme Mode: Up to 120+ Up to 250+HP
  • Number of Power Level Settings: 3
  • Performance Mode: 75+ 125+HP
  • Tow/Economy Mode: 50+ 100+HP
  • Select Power Level On The Fly: Yes
  • Speedometer Correction: Yes
  • Internet Updatable: Yes
  • Top Speed Adjustment: Yes
  • Rev Limiter Adjustment: Yes
  • Monitor: Included
  • Automatic Transmission Adjustment: Yes
  • Reads Trouble Codes: Yes

Main Features

  • One of the leading brands in terms of diesel performance.

  • It can tune your engine up to 250HP of power that is much higher than any other unit. 

  • Installation procedure and setup protocol are not very hard to follow.

  • It offers you a choice to select between the four different performance modes.

  • Two separate day and night display features are built-in to provide better visuals and improve readability. 

Bully Dog is the pioneer of diesel performance. This little gadget is one of their best-selling aftermarket products. It is a great device that adds more power to your engine by breaking it from the hold of stock settings. Though you can revert to the stock settings when you like, the tuned settings are certainly much better. 

Amongst its four performance modes, you can choose the one that is more suitable for your usage. Once you select it, the GT will apply the selected tune to improve the engine's performance and torque. It also enables the vehicle to conserve fuel, saving you some money in the long run.

It is supplied as a complete kit. You will find everything you need to successfully install it inside the package. The kit includes a micro SD card, a card reader, programmer display monitor, HDMI cable, adapter, a DLC cable, a power key cable, and a mount to set the monitor on. 

You will just need a computer to download the update agent. It is available to download for free on the website. This one software is enough to handle all the varying car makes, models, and years the GT is compatible with. 

Last but not least, the display monitor is very thoughtfully designed. It looks nice on your dashboard, yet it is sturdy enough to handle the roughest of the rides.


With the Bully Dog GT in your vehicle, you can enjoy several benefits, including:

Allows You to Monitor Critical Engine Data

The Bully Dog GT Platinum Diesel Tuner keeps a close watch on your engine’s condition and displays all the recent data on the monitor. This way, it not only allows you to keep track of the engine’s performance but also acts instantly if there is any problem. It not only prevents engine malfunctions but also saves you from spending extra cash for the repair costs that would have been otherwise needed had the GT not cautioned you to act. 

Display Has a User-Friendly Interface

Although the display screen is not touch-enabled, it is still very easy to use. With its colored graphics, it is effortless to read and operate. Numerous color schemes also add to the readability. You can choose one to match your car’s interior or to represent any special occasion. There is also a separate day and night display sequence mode for better readability in those conditions. Also, the buttons are soft to press and respond promptly to the minimum pressure. 

Safer Defueling

It keeps you safe and protected. Using it’s safety defueling feature, it cuts out the fuel if any risk arises. For example, if your vehicle is experiencing high exhaust gas temperatures, transmission temperature, or over boost, the tuner will shut off the fuel supply to neutralize the risk. This capability is a feature that you do not find in many diesel tuners. It also shows how much thought was put into designing it. 

Preloaded Tunes

The GT is pre-programmed with four different tunes. They are also known as performance modes. Using these, you can easily set up the goals you want to achieve while driving. Be it a high horsepower, fuel economy, or torque, it lets you tune your engine progressively up to 250 HP. But gaining that much also depends upon the application you are currently running. 

Supplied as a Complete Kit

This tuner is helpfully supplied as a complete kit. It includes all the necessary hardware you will need to set up and mount the programmer on your vehicle. From the micro SD card to the power key cable, everything is included in the package. Additionally, the update agent software is also free to download from the Bully Dog website. The installation is also a breeze. Even the person who is new at this will be able to work out what to do. 


On the other hand, some common drawbacks you will experience include:

Lacks a Touch Screen Display

Today is the time of touchscreens. You can achieve a lot with a single touch placed at the right spot. Judging from the multitude of touchscreen displays around us, we can realize what the GT Platinum is missing. 

The buttons are very simple and comfortable to use. The colored display is very attractive and readable. The day and night time display features are there. And you can also customize the color scheme. However, the lack of a touchscreen is something we cannot digest.

Technical Support is Not Readily Available

This is a big issue that users have been facing over the years. The Bully Dog technical support is just available during the working hours of a business day. Your call won’t be attended if you try to reach them on the weekend. The problem is so frustrating now that more and more new users are only installing their GTs during working hours so that technical support can be contacted if the need arises.

What Does a Bully Dog Tuner Do?

The Bully Dog Tuner is a plug-and-play device that is designed to bring out the best of your engine’s power output. It is a highly useful gadget that can not only save you some money but also keep your vehicle in an optimum condition. Hers are some more purposes that the Bully Dog GT can serve. 

Improves Torque and Horsepower

A Bully Dog tuner is effective in improving the horsepower and torque of your vehicle. With added power, the engine works efficiently, and you can cruise over the bumpiest roads without any difficulty.

Saves Money

We all know that diesel-operated vehicles consume a lot of fuel. Having a Bully Dog installed over one will greatly improve its fuel efficiency. Using less fuel, it will save you some money in the long run. 

Puts the Control in Your Hand

This is a highly acclaimed use of a Bully Dog. Vehicles are manufactured pre-tuned. A GT will break the hold of the pre-programmed tuner and allow you to take complete control of the vehicle. Now you decide how you want to tune it without needing a mechanic or dealerships to do it for you.

What Do I Need to Know Before Buying a Bully Dog GT Platinum Diesel Tuner?

With the multitude of products available on the market, finding the right one is not easy. If you really want to upgrade your vehicle's performance and overall quality, you need to choose a unit that guarantees great quality. Here are some aspects to consider when buying a performance tuner for yourself.


The first and foremost thing to know is the amount of money you will be spending. Vehicle tuners come in a vast range of prices. We urge you to carefully assess the different models as a higher price does not always mean better quality or performance. You can get a quality performer at a low price range too. It is also better to invest in a unit whose price falls within your budget. 


The second top priority should be the features. After careful examination of different models, you will note that most of them offer the same features. But some units will stand out from the rest because of more improvement in horsepower, torque, and fuel economy. 


The sole purpose of a tuner is to bring about an overall improvement in your driving experience. You must look for a unit that will unleash the full potential of your vehicle. The device should allow you to take control of every aspect of your truck. 

Data Monitoring

A good tuner will allow you to record data collected over time. You can view it any time you want to learn more about your vehicle’s functionality. Modern units feature cloud-based restoration that allows you to access the saved data. 

Ease of Installation and Usage

No one likes going to the workshop for minor issues. You should purchase a tuner that is not only easy to operate but also effortless to install. It does not hurt that you can install it on the vehicle yourself.

The units manufactured these days are all about facilitating their users with easy installation and functionality. 

Bully Dog 40420

Brand Comparison Overview

GT is one of the Bully Dog’s best selling programming kits. Over time, its popularity has not lessened. Here is how it compares to know of the other brand programming chips. 

SCT Tuner vs. Bully Dog

Both SCT and Bully Dog are respected names in the automotive aftermarket accessories world. Let’s look at their similarities and differences. 


Their tuners are known to deliver high power and fuel efficiency. You can feel how different your vehicle moves once you have either of these installed. 


We found that Bully Dog is more of a one-size-fits-all kind of a tuner. A single application can tune all models from a certain year group. Meanwhile, the SCT takes a more customized approach. Their tuners are designed to tune any vehicle according to its requirements. 

Edge vs. Bully Dog

Edge, like the name suggests, has been adding edge cutting power to different vehicles. Here is how it compares to the Bully Dog. 


Again, both are vehicle efficiency programmers. They save you money in terms of fuel efficiency and keep your vehicle safe by making it cruise over the rockiest roads most smoothly. 


The differences between their performance are not very noticeable. However, consumers say that the gauge installation of Edge is better than Bully Dog. 

Superchips vs. Bully Dog

We like the high-performance chips of both Superchips and Bully Dog. Here is a comparison overview of their similarities and dissimilarities. 


Superchips and Bully Dog offer better torque and overall performance than any other brand in the market. You will notice an instant boost in the overall performance of your truck with any of these on. 


Superchips allows you to log performance times and speeds while enjoying on-the-fly adjustability. Bully Dog manufactures solid overall performance chips for cars or trucks. 

Bully Dog vs. Diablo Tuner

Bully Dog has gained the reputation of producing some of the best tuning hardware. But Diablo tuners do not lag in any way. Let’s look at their similarities and differences. 


Both devices have preset tunes to help you control your vehicle’s performance according to your needs. The tunes can be downloaded to your truck for better running performance. 


When it comes to tunes, while GT offers only four performance modes, Diablo Tuners can store up to five tunes with an option for tune customization. You can have a tuning set up according to your driving needs and routes. 

How to Install a Bully Dog GT Platinum Diesel Tuner

Bully Dog GT Platinum Diesel Tuner is one of the best selling accessories for diesel trucks. It is a versatile unit that allows you to adjust your vehicle’s power and performance according to your preferences. Installing one on your vehicle is not hard; you will only need a computer to program. Here’s how to do it. 

  1. The first thing you need to do is install the update agent on your computer. Open the Bully Dog website and download the update agent.

  2. Take the micro SD card, load it into the supplied card reader, and connect it to the USB port of your computer. 

  3. The update agent will prompt you with a product registration form. You can go ahead and fill it out. 

  4. After registration, unplug the card reader. Take out the memory card and put it on the Bully Dog Tuner. 

  5. Connect the tuner to the computer via the USB cable.

  6. Once your programmer has booted, go to the main menu. 

  7. Choose the "change the vehicle" menu. 

  8. Select the make of the vehicle you want to sync it with. 

  9. Now select the model, engine size, and the year.

  10. Confirm the vehicle by pressing yes and wait for the process to complete. 

  11. Unplug the tuner. It is now ready to go inside the vehicle.

  12. Turn the ignition key on the run position. Take a test light and use it to find a powered knob in the fuse box. 

  13. Turn off the ignition and connect the kit’s power wire here. 

  14. Take the HDMI cable and connect it to the programming chip. 

  15. Take off the dashboard side panel and snake up the HDMI cable through. 

  16. Set up your programmer mount near the steering wheel and load the GT on to it. 

  17. Next, take the other end of the HDMI cable and plug it into the adapter. 

  18. Switch the adapter to the battery. 

  19. The adapter connects to the Diagnostic Lock Connector (DLC) cable. Connect it to the DLC connector located under the dashboard. 

  20. Turn the ignition key to the run. 

  21. Open the main menu. 

  22. Select install update and follow the instructions. 

  23. Now unplug the SD card, reload on the card reader, connect it to the computer, and open Bully Dog update agent. It will upload the stock files to the update agent. Download the update to the card. 

  24. Now put the SD card back into your GT.
  25. Go to the main menu, select install updates.

  26. Agree to the warranty, usage, and battery condition disclaimers. 

  27. Let the processing complete. In between, you will be asked to switch the ignition key. Be sure to comply. 

  28. From here on, it is a matter of selecting certain functions and parameters of the tuner’s capability to control or modify the truck’s engine capabilities as well as other functions to vehicle systems.

  29. Once the programming is done, you can switch the adapter to the key and start using your GT.

The procedure may look lengthy and complicated. But trust us, it’s not. Even a newbie can do it in as little as thirty minutes. Here is a video for your ease. 

How to Change Vehicles on a Bully Dog GT Tuner

Bully Dog programming Tuners are designed to work on a single vehicle only. Once you sync a Bully Dog Tuner to your car, it will read and save your Vehicle Identification Number (VIN) and lock itself on to it. Even if you try to set it up for a different vehicle, it will display some kind of error. You have to get it unlocked from the manufacturer to be able to use it in another vehicle, that too, for a hefty fee.

Fortunately, you can do it on your own by making the tuner return back to its factory settings. Here is how. 

  1. Make sure your key is on.

  2. Open the menu and scroll down until you see “install GT.” 

  3. Check the vehicle application and press yes. 

  4. You will be prompted with a disclaimer. Scroll down to the bottom, and select agree. 

  5. You have to have the battery within good to excellent condition. Press continue. 

  6. Wait for the processing to complete. Follow the key instructions that follow. 

  7. Once done, your vehicle status will change to not be installed. 

  8. Now you can go to the “change the vehicle” option. 

  9. Choose the make of the vehicle you want to sync it to. 

  10. Select the model, and the GT will download the application for the new vehicle. 

  11. Be sure to keep the status at “not installed.”

We understand that following theoretical instruction is hard. That’s why we have included the videos of uninstalling and changing the vehicle below. Be sure to check them for a better understanding. 


Bully Dog GT Platinum Diesel Tuner is no doubt one of the best vehicle performance tuners available on the market. Once you install it, you will notice an immediate improvement in power and fuel efficiency. It also offers different performance modes for you to choose from. You can easily manipulate the factory presets and drive on your own terms. It breaks the factory’s stranglehold and allows you to take control of your truck’s performance. 

People Also Ask

Diesel tuners have been a phenomenon from the first time they were introduced. Bully Dog has gained the reputation of producing high-quality and reliable performers that can jack up the performance of any vehicle they are installed on. If you are still confused about purchasing one of their units, here are some frequently asked questions that will help clear your confusion. 

Are Bully Dog GT Platinum Diesel Tuners Worth it?

Judging from the immensely positive feedback backing them up, Bully Dog GT Platinum Diesel Tuners are certainly worth it. They give your truck’s performance a boost and ensure that it runs smoothly. Installation is a breeze, and with regular software updates following it, you can’t go wrong with purchasing one of these. 

Who Makes the Bully Dog GT Platinum Diesel Tuner?

Bully Dog manufactures the Bully Dog GT Platinum Diesel Tuner. The company was established in American Falls, Idaho, in 1998. It originated when a local business turned its attention towards the much-needed improvement of diesel engines. 

When Was the Bully Dog GT Platinum Diesel Tuner Created?

Following its predecessor, the Bully Dog GT Tuner, the Bully Dog GT Platinum Diesel Tuner was created in 2009. It was made available for purchase in the same year. Being a bestseller, Bully Dog decided to improve and give it a makeover for more efficient and versatile all-round performance. 

Is a Bully Dog GT Platinum Diesel Tuner Hard to Use?

No, the Bully Dog GT Platinum Diesel Tuner is not hard to use at all. It features a full-color display with buttons on both sides to facilitate usage. Although it lacks a touchscreen interface, we find that not to be a big problem. With one of these, you will improve your engine's performance and change your driving habits to more efficient ones. 

How to Reset the Bully Dog GT Tuner

When you install a Bully Dog Tuner on your vehicle, it locks itself on to that vehicle. You cannot use it on any other vehicle without resetting it first. Unfortunately, it is the manufacturer’s trick to prevent buyers from using one tuner on multiple cars. They want to be paid for every car their tuner is working on, so they have set up a fee for unlocking or resetting it.

How to Update a Bully Dog GT Tuner

Updating your Bully Dog GT tuner is not a tough task. Take your tuner and connect it to a computer. Or you can also remove the SD card and connect it via a card reader. Now open your update agent and choose the card and click select. 

Go through the device list, select your device, and press download and update. Once downloaded, disconnect the device from the computer. Turn it on. Open the menu, scroll down, and select update software. The tuner will update itself with the latest files. 

How Much Horsepower Does a Bully Dog GT Add?

The Bully Dog GT is its flagship product. This is a versatile four-in-one product that can add up to 42 HP to your system. It also reduces fuel consumption and provides diagnostic information amongst a wide array of features and functions. 

Does a Bully Dog Improve Gas Mileage?

Bully Dog is good at maintaining and improving gas mileage. Whether you are driving on a smooth road, a highway, or on an off-road track, you will find that it does not disappoint. It delivers a definite improvement thanks to the new Driving Coach feature that constantly reminds the driver to lay off-gas.

Sean comes from the forums actually and drives an OBS Ford. He writes fantastic DIYs and knows his way around a camera, too. We keep him caffeinated and away from DPF filters to avoid another rant about recent emissions restrictions.