Thor Forums

[Chance]

Simple math says that 320 HP in a 20,000-pound motorhome plus toad (more or less) will result in power to weight similar to putting a 64 HP engine in a 4,000-pound car. If you did, the transmission would be shifting a lot too and the engine would run close to redline on uphills.

Downshifting for engine braking has similar limitations. A 6.8L V10 may seem large, but relative to weight, it’s like a 1.4L tiny gasoline engine trying to slow a 4,000-pound vehicle. It’s going to scream if driven like a normal car.

Easiest solution is to slow down on both uphills and downhills if one wants to keep RPMs much lower. On downhills it’s often necessary to first apply brakes to slow down enough so that engine braking can provide enough braking force in a much lower gear to keep from speeding up again. Unfortunately, that means going downhill much slower than auto traffic.