low end motors vs high end motors

[BrianG]

That would be tough to do. You'd have to repeat the run EXACTLY the same way to be of any statistical use. It would probably be easier to hook the motors to a constant mechanical load and then time how long each runs before the pack dies. Then, repeat the test at various speeds to emulate partially loaded operation. Compile all the data, and make a nice Excel spreadsheet complete with graphs!