I added a bionx 250pl system to my bike and I get about 30-35 miles range at level 3 assist. I use 700x28 wheels, btw. To get an idea of how much assist level 3 gives, that assist level raises my average cruising speed from 18mph to 22 mph. 18mph was what I had before I installed the kit onto the bike. The assist levels go from 1-4.