Why do you Cummins guys want more gears
I’ve heard a number of Cummins fans saying they are waiting for an 8 or 10 speed transmission before getting a new truck. Why? Does the Cummins struggle to get your trailer moving from a stop? Or are ...
Forum Discussion
Groover wrote:
Engines that are not working at full throttle can compensate for too high of gear ratio by substituting torque for RPM. When you are running near full throttle much of the time you can really notice power drop off when the transmission goes up a gear.
Most of the people here are using pickups that are generously powered for the load that they are moving. On the other hand, the Cummins in my motorhome is moving 30,000lbs with only 300hp and 600lb-ft of torque. Whenever the transmission upshifts to 4th or 5th gears I lose nearly a third of my RPM and a lot of my acceleration or hill climbing. I would dearly love to have another gear in that range as well as a lower first gear so things would get moving a little more quickly while waiting for the turbo to wind up.
So yeah, I would love to have 8 to 10 gears to choose from. Or 400hp and 900lb-ft or torque. Either would accomplish a lot.
What you are experiencing is the lack of torque rise in your current engine. If you made 300 HP at 2800 and 788 lb ft of torque at 2000 you would have a perfectly flat power curve from 2000 to 2800 rpm and there would be absolutely zero power loss going from one gear to the next. The 2021 Cummins only loses 20 HP jumping from 3rd to 4th gear and less on the 4/5 shift and 5/6 shift.
