It can, but it gets really complicated really fast. More voltage can mean more speed, which can then mean more drag, which can actually make for more current draw. It "all just depends" in reality, there's too many un-stated variables. A lot of the current draw is just how you drive it, how you gear it, how fast your running and on what terrain. If you're on a tough terrain, doubling you speed and mean 4x the current or more.

Basically just decide what you are trying to do, ie. what vehicle, how fast in terms of top speed, how much runtime you want, typical terrain you'll be running on, and then post that as in "how do I get here" and you'll get pleanty of useful help from there. Ignore the 'fanboy' posts (ie. I think you should use this b'cos I used it and it's the best, it rocks!) and look for a majority or consensus, most of the advice you'll get tends to be pretty good.