I think, there is no change in range, because range is a 99% matter of speed and driving style, but no matter of enginerevs! The effect is in my opinion the other way round: The higher You rev, the more voltage (V) the engine gets, the lower You rev, the more current (A) is flowing. Higher current means more losses in energy into heat. So i would try higher engine revs than lower! So dont compare consumtion with carburating engines!