2013 Dodge 3500 DRW Gear Ratios

transamz9 wrote:

ah64id wrote:
Just did some quick math on the subject.

Lets assume pulling a grade at 55 mph using max torque and a flat value of 800 since I can't find the actual curve.

4.10's in 4th (direct) is 2450 rpms. 800*1.0*4.10 = 3280 ft/lbs to tires
3.73's in 4th is 2200 rpms. 800*1.0*3.73 = 2984 ft/lbs to the tires

So assuming that the 3.73 truck can hold 2200 rpms with 800 ft/lbs the 4.10 truck could decrease the power output to 2984 ft/lbs at the wheels or 727 ft/lbs at the motor. Less power means less fuel, less heat, and less stress.

Both trucks can do it, but which one is doing it easier?

There is no doubt that the 3.42 and 3.73 truck can pull like no tomorrow, especially compared to several year old trucks... but if your going to do it, do it right.. just my 0.02.

Or I can just put my 3.42' in third and have 3666 lb/ft. 800*1.34*2.42=3666. My truck has 850 lb/ft also.;)

With 28K combined I pull every grade border to border along I-5 at 55 or more. On the 6% grades I am running 2,800rpm or more in 3rd with 3:42 gears.

I am happy with the gears but I will be more happy when I get a 15 with the Aisin and 4:10's.