A hybrid vehicle is a vehicle that is powered by two or more power sources to move the vehicle (Lampton 2009). Among the types of power sources are electricity, petrol, and hydrogen gas. As of 2011, the world’s best selling hybrid, the Toyota Prius, on sale since 1997 has sold over 3 million units worldwide. Sales of other hybrids are also picking up. (Schwartz 2011)
There are 3 different power trains that are used by production hybrids. Only 12% of survey respondents knew this (Personal Survey 2012).
The parallel hybrid system involves an internal combustion engine and an electric motor that assists the engine to provide torque and power for the vehicle to move using a power splitter, a set of gears (Nice & Layton 2000). Since the electric motor used is small, these hybrids cannot be solely powered by the motor. In series-parallel hybrids, there is an internal combustion engine and an electric motor. The power generated by both sources can be used to drive the wheels or charge the batteries. The vehicle can be powered solely by the electric motor or the internal combustion engine or even both simultaneously (Nice & Layton 2000). In a series hybrid vehicle, the vehicle is driven by the electric motor only without mechanical connections to the internal combustion engine, which only recharges the battery that powers the vehicle when the battery charge is low (Wu 1995). This system was invented by Ferdinand Porsche, the founder of Porsche, in 1900 (Lampton 2009).
The first advantage is hybrid vehicles use less fuel than their petrol counterparts. This is because hybrids have an additional electric motor to help power the vehicle and reduce the strain on the engine, besides being able to shut down the internal combustion engine when idling. Hence, less fuel is required by the internal combustion engine to power the vehicle. Hybrids also have improved aerodynamics and use low rolling resistance tyres to reduce the friction experienced by the vehicle (Nice & Layton 2000).
Next, hybrids produce less emission compared to normal vehicles. Due to the reduced fuel consumption, these steps indirectly lead to less carbon dioxide produced during the combustion of fuel in the internal combustion engine of the vehicle. The lower emissions lead to a better environment as the greenhouse effect can be significantly reduced (Fuller 2009). Lower emissions also translate to lower road tax in certain countries like the United Kingdom (UK).
Hybrids also have tax exemptions and special privileges. Governments provide an exemption for tax as an incentive for buyers of these vehicles as these vehicles help to reduce the pollution in the environment (Fuller 2009). Some countries like UK provide exemptions for hybrids due to their low carbon dioxide output. Hybrids are fully exempted from road tax in the first year, if the hybrid produces less than 130 grams of carbon dioxide per kilometre, and full road tax exemption from the second year...