Brisk wrote:
Well.......I was expecting it to pull moderate hills in 6th like my buddy's 2010 ram with the 350hp/650tq motor and a similar trailer did. Turns out he had 4.10s. I am happy with the truck just questioning Rams logic with 3.42 gears. I would have opted for 3.73s or 4.10s so I could run 35" tires too.
You are actually putting down more torque at peak with your 3.42 than your buddy with his 4.10 in both 5th and 6th(and the rest of the gears).
Your truck in 6th with 3.42
800 x .62 x 3.42 = 1,696.32 lb-ft (rpm at 65 mph - 1,400)
in 5th
800 x .83 x 3.42 = 2,270.88 lb-ft (rpm at 65 mph - 1,875)
His truck in 6th with 4.10
650 x .62 x 4.10 = 1,652.30 lb-ft (rpm at 65 mph - 1,675)
in 5th
650 x .83 x 4.10 = 2,211.95 lb-ft (rpm at 65 mph - 2,239)
Both his 6th and 5th gear is barely outside Cummins recommended rpm range for efficient towing at 65 mph while your 5th gear puts you right at the optimum rpm range. Just think of your 5th gear as your towing overdrive when you need to be at the right rpm for pulling and your 6th as your empty overdrive to get better fuel economy when you don't.
