Yes, Doug's got it right. In this comparison we don't need any improvement to the electric motor at all. Any further improvements are quite marginal. It is already hands down capable of much greater efficiency with many fewer parts than an IC engine. It also requires much less maintenance, has excellent power, requires many fewer expensive external support components and a much simpler drive system by virtue of its far superior torque characteristic. It also starts easier, runs smoother and is virtually unaffacted by weather and altitude. In short, it is already far superior than an IC engine by just about every metric.

Now the batteries. Oops. Here's where it falls down. But as time goes on they just keep getting better. I remember flying electric aircraft on NiCds. Now, with brushless motors and LiPos the performance of electric power often exceeds glow or gas. This trend isn't going to stop.

No argument regarding the relative comfort, speed and utility of the automobile, however. It does come at a price mind you...