While it began life as an agricultural engine, its popularity picked up immensely once it was put into Dodge pickup trucks in 1989 and its industrial roots really began to shine. A simple design with unmatched reliability, tremendous performance potential, and rugged, million-mile durability sums up the appeal of the 12-valve 5.9L Cummins 6BT diesel engine. The 12-valve 5.9L 6BT came out of the box with a conservative 230hp, 440 lb-ft of torque, and a P7100 inline injection pump, but was easily capable of making more than twice that with minimal modifications using just basic hand tools. Going deeper into mods and engine tuning could push these 1,100 lbs. cast iron powerplants to 1000+ horsepower that would eventually cause the stock heavy-duty powertrain behind it to eventually implode without appropriate upgrades. Regardless of what you drive, if you’ve got a 12-valve 5.9L Cummins 6BT under the hood, you can expect it to keep hummin’ along for the long run.