Not disagreeing on that principle, but I think that is marginal compared to other factors. E.g. on freeway trips using AP you're at a pretty constant speed. It will have more impact on city stop-and-go traffic. Even then, it might still be be very minimal compared to getting the 4,400 lbs vehicle itself to move.If I were to guess why the other person got better efficiency, it's because a lighter wheel will give you less rotational mass, which is a big deal, as rotational mass takes much more energy to accelerate than non-rotational mass.