A hybrid vehicle is that type of vehicle that uses two or more different types of power sources to move or drive it. In most cases people refer to them as the hybrid electric vehicles or the HEVs which are actually a combination of internal combustion engine and one or even more electric motors.

The powers sources for hybrid vehicles include use of onboard or out board rechargeable energy storage system that is abbreviated as RESS. The vehicle also uses gasoline or diesel fuel as well as hydrogen, compressed air, wind, electricity, wind and liquid nitrogen. The hybrid vehicles use as many sources of energy and power as possible.

The engine types also vary with the types of hybrid electric- petroleum vehicles. These are internal combustion engines using gasoline or diesel engines that re powered by variety of fuels and electric batteries to power motors. Hybrid vehicles are grouped into these classes that include the parallel, mild and power split hybrid series hybrid and so on.

The parallel hybrid has its electric motor and internal combustion engine installed so that they can both power the vehicle individually or together. The internal combustion engine, the gear box and the electric motor are coupled by mechanically controlled clutches. For electric driving the clutch sandwiched between the internal combustion engine is open while the clutch to the gear box is busy. In combustion mode the motor and engine runs at the same speed.

The mild parallel hybrid use packed in electric motor that gives extra production during speeding up and also to generate on the deceleration phase. While the power split hybrid there are two electric motors and one internal combustion engine. One motor is the generator while the other motor acts as a generator. They are connected through a planetary gear set. On the open road the main power used is the internal combustion engine so that the battery’s life is maximally used while when maximum power is to be used for instance when overtaking then electric motors re used to produce that maximum power a short period of time. Examples of these hybrid vehicles include the Toyota Prius for the powers split hybrid and Honda Civic Hybrid or Honda Insight for the mild parallel hybrid

The Series hybrid uses electric motors that are powered by a single speed internal combustion engine. When operating at its most efficient single speed the engine drives the electric generator instead of directly driving the wheels. This engine can also do the following charge a battery, direct power to the electric motor and charge a capacitor. Incase large amount of power is in demand then the electric motor can drew power from a combination of batteries capacitors and generators. One phenomenon is that the series hybrid does not need batteries in its design because the capacitor can act as storage device.

Another subtype in the market now is the plug in hybrid electric vehicle or PHEV. This is a fuel –electric hybrid with increased energy storage capacity which in most cases is the use of li-ion batteries. These engines may also be plugged to mains electricity supply at the stop of the journey to avoid charging using the onboard internal combustion. This is an environmental preservation measure because the vehicle will emit a minimum amount of emissions or even avoid doing that at all.

Then lastly there is the fuel cell electric hybrid which is an electric vehicle that is equipped with a fuel cell. The fuel cell acts as the power source which makes the vehicle hybrid. These engines uses liquid hydrogen as fuel and powers the electric battery when it is depleted some of the examples of these vehicles include the Chevrolet equinox and Honda FCX

As Hybrid vehicles advance to have greater features, reliability, and affordability, we should see these vehicle become more and more popular with the common consumer.