Motors for these are usually brushed and range from 450-1000 watts. The brushes are an easy item to change - usually 4 plastic caps on the motor that you unscrew, pop out the old ones and pop in the new ones. They are usually geared and put out 1000 to 1200 rpms You may be able to "carry a ton with these" but they are made to be maintained, like european cars used to be, not made to be driven and ignored as we do with Japanese cars. The motors are not usually very durable - this based on reports from people I know here who have them. It seems like every few months they have some issues with them. My guess is that they go 10 mph tops, whether empty or loaded with medium weight. Speed limit for these kinds of vehicles in most cities in China is 12- 14 kph, about 10mph or less.