Unlike regular cars, hybrid cars employ more than one propulsion method by combining a conventional engine with an electric motor. The basic principle behind electric cars is that different motors perform optimally at different speeds.
The electric motor, for instance, is highly efficient at producing torque and aiding steering, while combustion engines are better at maintaining high speeds. A combination of both propulsion types produces excellent results in terms of energy efficiency, while also producing fewer emissions and therefore being kinder to the environment.
These are the most common type of hybrid car, an example being the Toyota Prius, which was the world’s first mass-produced petrol-electric hybrid. Parallel hybrid cars feature a system in which both power sources can directly drive the wheels.
This can be attained in three different ways; either directly by the engine, solely by the electric motor, or a combination of both. Again, we’ll look to the Toyota Prius to illustrate this point. For speeds up to 15mph, the Prius uses only the electric motor, with the petrol engine only coming into play when this limit is exceeded, making it ideal for short city commutes.
Most parallel hybrid cars also feature a regenerative braking system (RBS), which activates automatically when the driver decelerates or uses the brakes. Once activated, the RBS produces energy which is stored in the battery for later use, underscoring the energy efficiency of parallel hybrid cars.
Plug-in hybrid cars have conventional engines that are supplemented by larger batteries than their parallel counterparts. In some cases, these hybrids can travel up to 30 miles on electrical power alone.
As the name implies, plug-in hybrid cars can be plugged into an electrical outlet to charge. Contrary to popular belief, however, this needn’t be an external source like those on roadsides, as most PHEVs include an on-board power generator.
The main advantage of PHEVs is their capacity to displace emissions from the car’s exhaust to the generators which power the electricity grid. More often than not, these generators are renewable and usually produce lower emissions than a combustion engine.
Perhaps the least well known of the three, REX hybrid cars combine a combustion engine with an electric motor like other hybrids. However, the combustion engine’s sole use is to produce electricity for the generator that recharges its batteries, meaning that the engine itself does not drive the car.
The key advantage of range extender hybrids is their nullification of ‘range anxiety’, a phenomenon experienced by some drivers who worry about their battery depleting before reaching their destination. The inclusion of a combustion engine boosts the car’s range while also offering the option to refuel at a petrol station without having to charge the vehicle at an electrical outlet.
Despite their advantages, REX cars are experiencing a decline in popularity, which is most likely due to the rapid evolution of car battery technology and charging apparatus.
The popular BMW i3, for instance, launched in 2013 and offered both range-extender and electric forms, but only the latter version is still available.
Having covered the three variants, let’s take a look at some of the benefits of hybrid cars
By pairing an electric motor with a conventional engine, hybrid cars can significantly reduce carbon emissions when compared with petrol and diesel cars. The Honda CR-V Hybrid SUV, for example, emits 120g/km of CO2; a figure expected from a much smaller vehicle. Moreover, most new hybrid cars include a zero-emission mode for short distances.
Continuously evolving technology allows hybrid cars to optimise their fuel efficiency, so you don’t have to. For instance, Honda employs Intelligent Multi-Mode Drive (i-MMD) technology, which automatically switches between drive modes to align with the driving conditions. Toyota, on the other hand, puts the power in your hands, offering three on-demand driving modes - Eco, EV and Power - in addition to the Normal setting.
The latest hybrid cars incorporate smart technology that helps drivers cut costs. For example, many new models use fixed-gear transmission, which provides a direct connection to the moving components, resulting in rapid responsiveness and greater overall efficiency.
Simply decelerating and braking generates energy that charges the electric motor, ensuring that energy efficiency is maximised.
Due to their energy-saving power configuration and eco-conscious design, hybrid cars are often well worth considering, especially for people who frequently make short city commutes.
There are also legislative measures to consider, which are reflected in the sales numbers. For instance, hybrid car sales have grown steadily over the last decade, while the government’s plans to ban the sale of petrol and diesel cars by 2040 spurred further growth. Recent legislative changes, however, indicate that the ban may be brought forward to 2035, and will include hybrids, meaning that people will only be able to buy electric or hydrogen-powered vehicles once it comes into effect.