How Much HP And Torque Does A Stock 6.7 Cummins Engine Have? Here Are The Specs
The amount of horsepower and torque delivered by a stock 6.7L Cummins diesel engine depends on when it was released. The earliest versions of the 6.7 Cummins diesel, introduced around the middle of the 2007 model year for Dodge Ram pickup trucks, produced 350 horsepower and 650 lb-ft of torque. It was at that point in time that Cummins ushered in the 6.7 as the replacement for the 5.9 Cummins diesel which had peaked at 325 horsepower and 610 lb-ft of torque.
By mid-2013, horsepower ratings for the high output 6.7 Cummins diesel engine had increased to 385, and torque output climbed to 850 lb-ft. The latest iterations, produced after 2021, include standard output (SO) and high output (HO) versions of the 6.7 Cummins diesel. The current standard output 6.7 Cummins diesel puts out 370 horsepower and 850 lb-ft of torque, while the HO version makes 420 horsepower and 1,075 lb-ft of torque.
In case you were wondering about the horsepower and torque provided by the 6.7 Cummins gasoline engine, we're happy to report that Cummins rates its 6.7 gasoline engine, the Cummins B6.7 Octane, at 325 horsepower and 660 lb-ft of torque.
What improvements were made to the 6.7 Cummins diesel engines?
The original 6.7 Cummins diesel engine features the same inline six-cylinder arrangement and cast-iron construction as the 5.9-liter diesel it replaced. Its 13% larger displacement provided a platform to make more power than the 5.9, and it did so while meeting stricter emissions regulations right from the start.
The gains enjoyed by the 2013.5 engine were the result of Cummins' new SCR (Selective Catalyst Reduction) technology and advancements in the engine's fuel and air delivery systems. Those advancements not only improved the 6.7's torque output, but fuel efficiency was also improved by 10%. Plus, the maintenance interval for oil changes was extended to 15,000 miles, doubling the interval of previous Cummins diesel engines.
Since 2021, Ram 2500 and 3500 trucks have the SO 6.7 Cummins while only the Ram 3500 provides the HO 6.7 option. The most significant difference in the Cummins-provided specs of the two versions is the compression ratio. The SO 6.7 has a compression ratio of 19:1, whereas the HO's ratio is lower at 16.2:1. While the lower compression ratio for the HO 6.7 seems counterintuitive, it allows Cummins to dial up the turbo boost pressures to make more power when needed while keeping emissions in check.