11.   The electricity produced by the generator runs a traction motor that drives the wheels.

12.   The hybrid operates as an electric car under some conditions and uses the gasoline engine at other times to drive the wheels while also charging the battery.

13.   The robot steers itself by driving the wheels at different speeds.

14.   This releases a superheated steam jet that drives a turbine, which in turn drives the wheels.

15.   When the driver presses the accelerator, the momentum in the flywheel will be converted back into electricity to drive the wheels, cutting fuel use and pollution.