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
Even at the lower weights I'd say it's pretty accurate. I found a drag/horsepower calculator online, and at 65 mph it takes about 90 hp to move a high profile vehicle (80 square feet frontal area, 0.6 drag coefficient) down the road, without adding anything for weight or rolling resistance. On the same site there is also a rolling resistance calculator. For an 8000 lb vehicle add in another 20 hp for a total of 110 just to maintain 65 mph. This explains why smaller vehicles with engines that need to rev way up to get significant horsepower struggle so much with high profile trailers.
