just a little more power

parker.rowe wrote:

mkirsch wrote:


Not anymore. Most HD pickup trucks only have one gear option these days.

Not for gas trucks. Dodge offers 2 options, Ford offers 3. Gm is the only one that does not have an option. They haven't for a while iirc.

There are only 3 major manufactures of consumer HD trucks, and 2 of those offer different gear options, with increased tow ratings for deeper gears, for the gas trucks.

Issue with the RA deeper us better, it helps MOST in first gear assuming everything else is the same.

BUT, with my GM 6.5TD, on a freeway grade of 3-5%, with the nv4500 I had, the 3.73 would have been the better RA ratio. As the grade got steeper, I dropped a gear, I could go to redline in next lower gear, same speed as 1800 in higher gear.....reality, I would assume a high percentage majority of us do not drive at WOT in the gear below. We do as I did in that truck, reduce rpm to 2700 to 2800, drive whatever that speed is. With the 3.73, I would have been going faster bt 5mph or so.

Same thing occurs in my Navistar, having 7 forward gears, reasonably space apart, I've pulled hills better that higher up/torque motors with fewer gears. Both of these in first gear, due to lower overall ratio times torque, out pulled a basically double HP/torque Dmax. 6.5 by an additional%grade before stalling at 20k lbs. The IHC with lowest power, 30% at 30k lbs due to an overall low around 45-1 vs effective ratio of 17-1.

Iff you want to talk 4% freeway grade speed, the Dmax at 320 HP more than left the 175/185hp of the IHC/GM behind.

Reality, a lower ra may or may not help in actual towing experience. Depends upon the situation, what you want that truck to do or behave.

Marty