H - Hybrid
Hybrid - A hybrid car is one that uses more than one source of power. Unlike a bi-fuel car, however, which requires the driver to swap between power sources, a hybrid can swap between them as necessary while on the move, and can even make use of both when full power is required.
Most hybrids combine a petrol engine with electric power, the electricity recharging as the car cruises or brakes. Their main advantages are low emissions and excellent fuel economy. They are also exempt from London's congestion charge. Hybrid cars on sale in the UK include the Toyota Prius and Honda Insight.