> AIUI, increased grip due to weight scales linearly, whereas the increase in power required (and thus the increase in grip required) scales geometrically The

> AIUI, increased grip due to weight scales linearly, whereas the increase in power required (and thus the increase in grip required) scales geometrically The high-school physics model of grip has them both linear, but more sophisticated models may show a difference. (Interestingly, more mass on a vehicle does help when it is towing something heavy.)