Best Diesel Engine: 10 Most Reliable Units in 2022 ...
The most reliable diesel engine ever made was the 5.9L Cummins 12-Valve 6BT. This unit has million-mile durability, and it arrived factory with 230 horsepower, 440 lb./ft of torque, and an inline P7100 injection pump. Diesel enthusiasts from the era of the 6BT could boost horsepower to over 500 horsepower with ease.