Hybrid Cars: Under the Bonnet

Photo credit: Mike Babcock

Put simply, a hybrid car is one that combines an internal-combustion engine with an electric motor, powered by sizeable batteries, to propel the vehicle. There are two types of hybrid car: parallel and series (also known as serial). In the first case, both the combustion engine and electric motor are connected to the mechanical transmission, which means that both engines are capable of powering the car, at the same time or separately. In series hybrids, only the electric motor is linked to the transmission, and it alone propels the car. The combustion engine is connected to a generator and is used purely to recharge the electric motor’s batteries.

Nowadays, most hybrids use a combination of both systems, with power-split devices incorporated into the CVT transmission. The electric motor and the combustion engine are used to provide propulsion and the combustion engine is also connected to a generator that charges the batteries when needed. The device decides which motor to run and how to split the available power. The application of this system allows the use of an internal combustion engine with less power, which, in turn, reduces fuel consumption and emissions. So, when you’re driving at low speed, e.g. in heavy traffic, only the electric motor is used. As speed increases and the demand on the electric motor becomes too great, the combustion engine is started to not only aid in the propulsion of the car but also to recharge the batteries.

Another piece of technology that makes hybrids more efficient than regular vehicles is their ability to make use of the kinetic energy that would usually be lost while braking. When the brakes are applied in a hybrid car, the energy released is stored and used to recharge the electric motor’s batteries.

Today, there is a wide range of cars that incorporate these innovative systems. Last year, there were more hybrid launches than ever before as car manufacturers went head to head to try to meet the increased demand for these vehicles. The most popular and well-known hybrid model is the Toyota Prius; however, there are other models that are also worth attention. Honda offers a hybrid version of the popular Civic and there is also a brand-new original hybrid model from the firm, the Honda Insight. Meanwhile, more luxurious options are offered by Toyota’s upmarket Lexus division, in the shape of the GS450h, LS600h and RX400h.