In many ways, I think the mechanical-drive internal combustion engine is in its twilight years. A product that is in twilight years becomes incredibly complicated and convoluted compared to earlier versions. Modern mechanical-drive automatic transmissions, while reliable, are incredibly complicated with 8-9 speeds or more now the norm.

In contrast, electric drive cars, like on the Chevy Volt lack a transmission or have a simple gear box that goes between two speeds and primarily relies on the wide torque bands of electric motors. The two electric motors in the Chevy Volt provides all motive force -- the engine simply provides electricity to keep the battery charged or power the electric motors.

You get mechanical simplicity, great efficiency, and the ability to store energy as electricity in batteries that can also come from a grid. The internal combustion engine in the volt operates at a near constant speed, well in it's power band.

There is nothing that you can't not like about the Chevy Volt drive-train.