48V or 72V? Watt/hr + Peukert, etc.

I was going to go with 48V for my motorcycle. 48V X 55ah = 2640 watt/hr. If I go with 72V X 38ah, I get 2738 watt/hr, roughly the same. I am assuming that purely from a range standpoint, the 72V system will go farther because of less current draw and therefore less Peukert effect. Or do I just go with their [nearly] equal total watt/hr and assume that their ranges will be [nearly] the same?

James