A hybrid car is a vehicle that uses two or even more distinct sources of power in order to get propelled.

Among the power sources for a hybrid car there are gasoline or diesel fuel, on-board or out-board rechargeable energy storage systems (RESS), hydrogen, wind, compressed or liquid natural gas, solar, coal, wood or other solid combustibles, etc. The very concept of hybrid car designates electric vehicles that adapt the usage of an internal combustion engine to that of the electrical batteries.

As pointed out in the lines above, the range of hybrid vehicles is more extended than the category of simple cars. Just think of mopeds and electric bicycles. These are the rather basic forms of hybrid vehicles. The combination between a gas engine or a battery and the physical power of the muscles is definitely superior. Then there are hybrid heavy vehicles like railway locomotives, buses, heavy goods vehicles, ships or mobile hydraulic machinery.

Normally, the term hybrid car-vehicle is used to refer to hybrid electric vehicles. This range includes the next types of automotives: AHS2 (Chevrolet Tahoe, GMC Yukon, Chevrolet Silverado, Cadillac Escalade, Saturn Vue), Toyota Prius, Ford Escape Hybrid, Toyota Highlander Hybrid, Toyota Camry Hybrid, Honda Civic Hybrid, Honda Insight and many others. A gas-electric hybrid car usually takes its power from an internal combustion engine (gasoline or diesel engine) and an electric battery.

The origins of the hybrid car are to be found in the early 1900s when David Arthurs created the first hybrid ever. Besides the hybrid car as mentioned above, which uses two or more different propulsion devices, there are also vehicles which use distinct sources of energy or input types but only one engine. These are also considered by some people to be similar to the hybrid car. Actually the latter should be more appropriately called dual mode vehicles (electric trolleybuses, dual mode buses, flexible-fuel vehicles, etc).

A hybrid car presents a number of advantages from the environmental perspective and there are two sides to consider here. First, there is the aspect of fuel economy, and secondly, the benefit for the environment and, implicitly, for humankind is undeniable in the fight to reduce pollution.

These two advantages and benefits brought about by the hybrid car are tributary to at least three elements in the design: the combination of gasoline and the electric motors, a battery with plenty of storage capacity and the possibility to re-capture important amounts of energy, which are normally wasted while braking.