F350 Super Duty vs 3500 Denali vs The Ike Pulling 30k lbs

Cummins12V98 wrote:

4x4ord wrote:

Cummins12V98 wrote:
To have zero brake applications they need to be running at the speed they want to maintain then set cruise to say 5mph less but also lock the trans in the same gear you would have climbed that grade in. This will vary based on the grade and load. This takes a human to dial this in.

I easily maintained 30-35mph locked in 2nd gear on a several mile 14% grade at 33k combined simply by moving the cruise speed up or down with my thumb.

For the Cummins closer to 3k will give the best downhill braking.

Cool brakes along any big downhill grade = GOLDEN.

After appling a bit of physics to what you're experiencing I come away thinking your Ram must work similar to my Ford on cruise.... it applies the wheel brakes. Holding 33k on a 14% grade in second gear with 4.10 final gear ratio means about 1000 lbft at the crankshaft. If your engine is revving around 3000 rpm it would be producing about 575 reverse hp. The back pressure on your exhaust brake would need to be somewhere around 180 psi. So I think your truck must be automatically applying the service brakes.

It does not.

Something is not adding up. Could you possibly be in low gear? or could the grade be significantly less than 14% or you are accelerating down the hill? I've never been on a long 14% grade with a 25k trailer behind my pick up but I'm sure it would be a run away without using the wheel brakes in 2nd gear. 33k on a 14% grade would be like 66k on the steepest section of the Ike. The Duramax and Ford couldn't hold back 39k on the Ike.