[Andrew Blair]

I had a similar thought a couple months ago, and here's what I found out, as people have said above me: You really reap no power saving benefits by engaging and disengaging the extra motor. In a gasoline vehicle you would, because all the engines are running at generally full output all the time, but with an electric motor, the load is shared between the motors. So, if you have a single motor, you draw 40 amps, but with two motors, you still draw 40 amps, but each motor only draws 20. So now I thought, having learned the basics, why not just use one motor and save the weight? Well, by having two motors on thee, you really gain nothing except a cooler drivetrain until you start pushing. Then, when you could only draw, say, 40 amps through one motor, you can now draw 80 total, doubling your wattage to the wheels.