2021 Cummins 1075 lbft peak torque at 1356 rpm

4x4ord wrote:

wilber1 wrote:

4x4ord wrote:

wilber1 wrote:

4x4ord wrote:

Your thinking the torque is 1075 lbft from 1356 to 1800 rpm, then drops to 807 lbft by the time the engine hits 2800 rpm .... maybe, I hope your right but I'm not convinced. I wish they would publish torque curves.

Sounds about right. When Cummins went from the 650 Lb Ft to 800 Lb Ft in 2011. Both hit peak torque at 1600 and made the same peak 350 HP at 2800. The 650 torque curve remained flat until peak HP and the 800's torque gradually declined until it made the same peak HP at 2800 RPM.

It's impossible to know exactly what the torque curve would look like when we are only given power or torque at two rpm points. If the article I read is right stating peak torque of 1075 lbft @ 1356 rpm, then we know that point. It is only possible that the torque remains at 1075 for as long as 2100 rpm. Beyond 2100 rpm the torque absolutely drops off but it could just as easily be dropping from 1400,1600,1800 ... who knows, we can only guess. If peak HP is 430 HP @ 2800 rpm then we know the torque at 2800 rpm is 807 lbft. As the engine rpm drops lower and lower form 2100 rpm the less relevant the torque value is as far as describing how the engine will pull a hill. It would be nice if Cummins would rate the engine as making peak torque of 1075 lbft from 1356 to 1600 or 1800 rpm ... or what ever it is.

The big thing is useful power. The 650 and 800 Cummins had the same peak power at the same RPM but the 800 made 30 more HP at 1600 RPM which is a normal towing RPM and very useful.

Here is a quote from the article that mentions 1356 rpm as where peak torque is developed:


Ram and Cummins increased boost from the variable geometry turbocharger and upped the fuel delivery system’s flow rate. The changes for 2021 account for an additional 75 lb-ft. of torque versus a 2020 model. It’s worth noting the torque figure of 1,075 lb-ft. applies to the High Output version of the 6.7-liter Cummins Turbo Diesel, which is only available for the Ram 3500 HD. If you opt for a Ram 2500, the truck will come with the standard output Cummins engine with 850 lb-ft. of torque.

Another key difference is where the peak torque hits in the rpm band. The standard output Cummins provides peak torque at 1,700 rpm, while the High Output version will do so at 1,356 rpm.


The journalist was talking to a Ram engineer to get his information and after thinking about this I have a theory of a misunderstanding taking place. I’m thinking the engineer may have been comparing the standard vs HO engines. The engineer may have been talking about the rpm where torque is created and said something like “standard output engine makes peak torque of 850 lbft at 1700 rpm. The HO does that at 1356 rpm”. So maybe he was meaning the HO produces 850 lbft at 1356 rpm.

Until I know more I’m choosing to believe the new 2021 peak torque is 1075 lbft @ 1800 rpm.

The other attributes to consider is the HO has lower compression and relies on the variable vane turbo more than the standard engine that has higher compression.