Changing from 3.73 to 4.10 gears
Hello all, After towing our new Reflection 320MKS from Eastern Iowa to Estes Park Colorado and back, I need more power for the hills. I have a 2015 F-250 with the 6.2 Liter engine. I have 3.73 years...
Forum Discussion
To move out of the weeds and apply things to the OP's situation I think the OP needs to realize that the 6.2 liter engine makes 316 HP at 4200 rpm and 385 at 5500. If his loaded truck and trailer weigh in at 22000 lbs he should be able to pull a 6% grade at about 55 mph so long as he can keep his rpm above 4200.
55 mph means the rear axle is turning 578 rpm. If he goes up the hill in second gear with 3.73 rear end his engine will be turning 5002 rpm (2.32:1 2nd gear ratio x 3.73 x 578). At 5000 rpm he might even have enough power to accelerate to 5500 rpm (60 mph) where the engine makes peak HP.
So according to my math the 3.73 gears should allow him to put full power to the road at 60 mph on a 6% grade in 2nd gear.
If the hills are steeper than 6% he might benefit from a 4.10 rear end which would allow him to put full power to the ground at 55 mph.
55 mph means the rear axle is turning 578 rpm. If he goes up the hill in second gear with 3.73 rear end his engine will be turning 5002 rpm (2.32:1 2nd gear ratio x 3.73 x 578). At 5000 rpm he might even have enough power to accelerate to 5500 rpm (60 mph) where the engine makes peak HP.
So according to my math the 3.73 gears should allow him to put full power to the road at 60 mph on a 6% grade in 2nd gear.
If the hills are steeper than 6% he might benefit from a 4.10 rear end which would allow him to put full power to the ground at 55 mph.
