HP required to pull hills
Here is a formula that will give a rough idea of the flywheel HP required to tow a fifth wheel up a grade at speed. HP= s(53000+gw)/31800 s = speed (mph) g= % grade w= weight of truck and trai...
Forum Discussion
carringb wrote:
Don't forget to account for drag:
Air resistance (lbs) = fA x Cd x 0.00256 x speed squared (speed in mph)
Rolling resistance (lbs) = vehicle weight (lbs) x 0.015
Power (hp required) = Total drag x mph / 375
To keep things simple I've allowed 100 HP per 60 mph to account for drag and rolling resistance, which I believe is fairly close approximation for a typical 5th wheel. This is partly why I am suggesting it is an approximation. For most it is going to be close..... for someone like Cummins it might prove to give a result that is about 20 HP shy of actual.
The other assumption I am making is that there is a 15% power loss in the driveline.
