As I keep saying, this whole thing about range is nonsense. Some bikes get a long range by turning down the power. The less power the motor gives, the more you have to pedal. When you turn the motor down to zero, you have infinite range. Conversely, if you want to use a lot of power, you can't go so far. Most motors and controllers have similar efficiencies, althought the efficiency of the motor varies a lot with speed, so, if you have a motor capable of 20mph and you ride around at 10mph, you'll probably be making as much heat as motion with your motor and that will compromise your range.
So, there's two main factors which affect range: The first is matching the motor to your exact comfortable pedalling speed. The manufacturer has no idea who's going to buy their bike, so, any claims they make in that respect are nonsense. Crank-drive bikes have a theoretical advantage, but in practice your pedalling speed might still not match the motor, and pedal speed still varies a lot within each gear as you accellerate up through the gears, so in practice the advantage isn't realised. The second and most important factor for range is the number of watt-hours the battery can give. Many manufacturers' claims in this respect are also often unrealistic. Someone would need to measure the real-life watt-hours for each bike/battery.
In summary, the only worthwhile measurable for range is the actual watt-hours that the battery can give. If you want to go a long way without pedalling too hard, get a big battery and choose a motor speed that matches yours - unfortunately most manufacturers don't tell you the optimum speed of the bike for highest motor efficiency.
