[Roodgorf]

I think you just described 0 friction with 50% efficiency. With 100% efficiency the weight of the truck alone would be enough to recoup the energy on the way down.

[brianwawok]

Opps you are right. So we need like 40% effeciency to make this work?

[hexane360]

Yep.

efficiency * 110 tons * gh = 45 tons * gh

efficiency = 45 tons / 100 tons = 40.9%