Range can depend on a variety of factors, but the range specified on the website should be achievable by your average rider.
If you need more range, make sure you’re using Pedal Assist levels 1 or 2, and avoid using the throttle often. Also, make sure you’re using the gears properly. When first starting out, you want to be in a low gear (pedaling faster) then progress to a higher gear (pedaling slower / harder) as you increase your speed, just like a car would. If you leave the bike in the same gear all the time, you will see diminished range.
Take a look at our blog on using the CVT shifter, as well as our overview on Pedal Assistance and Throttles using the links below!