Bully Dog was founded in 1998 in Aberdeen, Idaho. Michael, Philip and Daryl Klassen, the founders of Bully Dog, were guided by their father Harold's interest in enhancing the performance of vehicles he used in his everyday life. A few years before Bully Dog began, Harold had injected propane into the engine's combustion chamber of his diesel farm tractor in the hopes of improving performance. In 1998 Bully Dog's founders took this research a few steps further and designed a safe and effective propane injection system to enhance diesel engine performance and then patented it. They first sold these systems out of their farm shop, but as demand increased they then moved the company to a different location and Bully Dog was officially organized. Bully Dog's quest to become the foremost company in the diesel performance industry inspired them to keep up with new innovations in this industry. The introduction of electronic components and software to improve performance prompted them to investigate new types of products like intake and exhaust systems, as a companion to their electronic components. This allowed Bully Dog to offer a complete performance package and in 2005 they expanded their offering of products to include gas powered vehicles. Bully Dog products are designed to allow each driver to achieve the results they are looking for, whether that is extreme performance on the race track or improved fuel economy in normal everyday driving. Bully Dog products improve performance, add safety and enhance economy.

In order to ensure that Bully Dog products equal and surpass your expectations, each product undergoes a detailed and rigorous research and development process. Once a design is agreed on, each product is subjected to months of challenging testing all over the United States to ensure that every product works as it should in all different conditions, various elevations, weather conditions and driving situations, from towing a heavy load to racing. Bully Dog believes that forward-thinking products are what keeps them on top of the industry now and into the future. Over the years they have been the first company to market with over 100 products and have also received many awards for their innovative products. With the release in 2005 of the Triple Dog Downloader and Outlook Monitor, Bully Dog brought the ability to adjust power, safety and economy levels while driving down the road to the market. In 2008 Bully Dog launched the Triple Dog Gauge Tuner, an amazing tool which combined a vehicle engine tuner, monitor, gauge and diagnostic device into one unit. The GT watches over more than 15 vehicle parameters (PIDs), and also has a Driving Coach feature which literally teaches drivers to maximize their vehicle's fuel economy capabilities. The GT also gives you the ability to monitor vehicle diagnostics and even erase diagnostic trouble codes. The GT is the most fully functional tool around and works on the widest variety of gasoline powered vehicles. The WatchDog, a digital gauge/monitor with a valuable Driving Coach for gas and diesel powered vehicles was introduced in 2009.