2020 Ram 2500 CTD owners

"You do realize the newer trucks have an 8 speed transmission"

You know something I don't know???

M.R.E. wrote:
I have a '16 Ram 2500 CTD that I love except towing. I wish it had the 3.73 rearend instead of the 3.42. What is your rpm at 7o mph in 5th and 6th gears ?

PLEASE explain what you don't like. You towing at 70 all the time?

You would be looking at only a 9% increase going to the lower gear ratio, barely noticeable. As ShinerBock said, just lock out 6th gear when towing unless you have some other reasons for changing the gears. That way the engine will turn a more reasonable speed when not towing too. And don't forget that tire size affects rpm as well. Newer trucks seem to be trending towards larger tires so they need the lower gears to get the same power to the ground at any given speed.

valhalla360 wrote:


You do realize the newer trucks have an 8 speed transmission,

The diesels don't.

valhalla360 wrote:

M.R.E. wrote:
I have a '16 Ram 2500 CTD that I love except towing. I wish it had the 3.73 rearend instead of the 3.42. What is your rpm at 7o mph in 5th and 6th gears ?

You do realize the newer trucks have an 8 speed transmission, be careful that you are comparing apples to apples.

Only the gas engines have the 8 speed. The diesel's have the same 6 speed trans as previous year models.

The math is telling me that a 3.73 CTD with a 68RFE at 70 mph, 5th will put you at 2,170 rpm (which is too high IMO) and 6th with put you at 1,652 rpm (which is too low for EGT's). The 3.42 rear end at 70 mph in 5th is around 1,990 which is ideal rpm to keep EGT's low without revving higher than necessary. This is why many recommend towing in 5th with 3.42 gears which will actually have more torque multiplication than a 3.73 geared truck in 6th while putting you at the most efficient rpms for towing per Cummins.

M.R.E. wrote:
I have a '16 Ram 2500 CTD that I love except towing. I wish it had the 3.73 rearend instead of the 3.42. What is your rpm at 7o mph in 5th and 6th gears ?

You do realize the newer trucks have an 8 speed transmission, be careful that you are comparing apples to apples. The link below shows the gear ratios.

https://www.cars.com/research/ram-2500/specs/

Assuming you pick a transmission gear ratio that is the same (it might not be exactly the same)...going from 3.42 to 3.73, should bump the RPM up by about 9% but in reality, the newer truck will likely select a different gear such that the overall gear ratio from crank shaft to wheel stays where the engine is happiest and with more gears to choose from, it can do a better job.