2021 Cummins 1075 lbft peak torque at 1356 rpm

Grit dog wrote:
......:h

Consider the torque rise as an engine resists a load. If a truck is pulling a heavy load up a hill you downshift and get your rpm up. As you start climbing, the hill causes the engine to slow. The Cummins has enough torque rise that it can pull down to about 2100 rpm in direct (4th) where it is putting about 1030 lbft of torque out the back of the transmission. After the shift the engine revs to 2800 rpm where the engine torque is only 788 lb ft. The 3rd gear ratio (1.33:1) increases that torque to 1048 lbft and the torque carries on rising as the engine continues to pull down in third gear. The Powerstroke, with its 10 speed would pull a hill the best running in the 2400 to 2900 rpm range.

It is interesting to view the rpm range where the different engines should run at looking at their HP graph. Here is a HP graph generated from the torque graphs that I posted earlier: