How Does A Hybrid Car Work?

Firstly, hybrid cars are not an electric car. They have both an internal combustion engine and an Electric Motor. Therefore, they start the same as a “normal” vehicle. This advanced combination enables the electric motor to help the conventional engine operate more efficiently, saving on fuel usage.

Whilst, the petrol engine enhances and increases upon the performance limitations of a purely electric vehicle. This also means that you can purchase a larger car without the larger normal engine because you have to fuel efficiency of a smaller car. Here then, we begin a series of items which will attempt to demystify some of the terms which you may come across within your car warranty policy. We hope that you find them illuminating reading...


At a standstill petrol engines are poor in their efficiency, whereas an electric engine is 90% efficient, giving almost maximum power. Hybrid cars have the petrol engine downsized and the electric motor is added to help acceleration. So, maximum power from rest reduces acceleration strains from the petrol engine, thereby saving fuel and increasing efficiency at the same time!

Different Hybrids


There are now a variety of different hybrids on the market and each generation has attributes not seen before. The standard rule is that unless your driving a new generation hybrid like the Prius gen2 your vehicle will determine when to switch between battery and engine modes for you, even when cold! The 08 FEH 4WD mainly found in the USA has a unique system where it warms up the batter cell when left outside under extreme temperature.

By slowly charging and discharging the cells the car is able to warm about 10'F for every 10-15 minutes of drive time. The newer Prius Gen2 gives new car buyers more choice and they are able to select drive modes. Under normal circumstances though the Hybrids electric motor will then continue until speeds of around 15mph, or 30mph if you take it really slowly. It will then kick back into the engine, so the slower you accelerate, the less you use the petrol engine, hence the fuel saving efficiency of them.

Other models will use the normal engine until the first time you slow down and come to a stop then the electric motor will kick in, as mentioned above this is in complete contrast to the older Prius models which always select the best combination for the driver.

All hybrids when coming to a stop are running on the electric motor, therefore no CO2 gasses are being produced, enabling money saving and the environment.

But where does the electric power come from?


Whilst the normal engine is on, it also keeps the electric batteries charged, these are made from nickel metal hydride. Hybrids also use a technique called regenerative braking so when the car is slowing; the electric motor is used as a brake. Also when you brake, that energy from braking is converted to power which is then stored in the batteries. All of that stored power is then transferred to the electric motor when required. It is power efficient too, so instead of storing excess energy or trying to save it when not needed, the petrol engine it switches off. So when slowing down or stopped, the petrol engine is switched off. 

Not all hybrids are the same. Some, like the Toyota Prius, which is the most popular of models, have the electric motor and petrol engine working separately and independently from each other. Therefore, allowing the car to be power by either or both methods. At low speeds the car is then powered completely by electric. A huge advantage in city driving. Then at higher speed the car uses a little of both, meaning that the battery power aids the petrol engine, adding power and reducing the need for additional power to be created by burning more fuel.

Others such as the Honda Civic IMA, use both methods together. Naturally this is more efficient for higher speeds, but uses the petrol engine more. Hybrids are best used for short and medium journeys. Those that include stop starts and non motorway driving. Basically, commuting to and from work. Hybrids also are more expensive to purchase, but company car tax and road tax costs are greatly reduced, as are the running costs. It is expected that high mileage users are the ones to benefit most and to save money on a hybrid car compared to buying the equivalent petrol model.