[redpoint5]

Another thing I have pondered with regards to hill climbs and efficiency is speed. Consider that it takes energy just to maintain position on a hill. You could burn fuel just sitting in one place at a standstill. Let's say it takes 1hp to just sit there and not move. If you double the horsepower by giving more throttle to the engine, then you are spending 1hp to merely maintain your position on the hill, and 1hp is spent actually climbing it. That would be a very slight throttle opening, and half of the power would be wasted to just maintaining hill position. If you increased throttle opening even more and now were developing 10hp, 9 of those would be spent climbing the hill, and only 1 maintaining. In this example, increasing power from 2hp to 10hp increased hill climbing efficiency from 50% to 90%.

Since just spending time on a hill without climbing it consumes fuel, it follows that getting to the top of the hill quickly reduces the amount of fuel wasted just maintaining position. Getting to the top in 1min instead of 2min reduces this wasted "maintenance" fuel expenditure by half.

The only factor that makes it more efficient to go slower, and this is significant, is wind resistance. There is some sweet spot of speed where getting to the top quickly is balanced by the exponential forces of wind resistance. Finding this ideal speed for various hills seems a daunting task for this limited mind to figure out.