Since 1998, Bully Dog has been developing ways to improve diesel performance. Originally, they used propane to enhance the diesel engine's performance during the combustion cycle. Soon after, Bully Dog began developing electronics, exhaust systems and air intake systems to complement each other and take diesel performance to the max. Bully Dog's systems are designed with quality and functionality in mind and are versatile as well. Whether you're looking for outrageous racing power, pulling power, fuel economy or just a mild upgrade, Bully Dog has the products that you need, many with safety features built in for your additional piece of mind. The Bully Dog name is continually mentioned when talking about the major players in the diesel performance industry and with good reason.