How do hybrid cars work?

Interested in learning more about hybrid cars and how they work? In this article, we discuss everything you need to know about hybrid cars, including what they are, how they work and the different types of hybrid vehicles available.

Firstly, before we get into exactly how hybrid cars work, let's first look at what hybrid cars are and when they were first introduced to the automotive industry.

What is a hybrid car?

A hybrid car is a vehicle that combines a traditional combustion petrol or diesel engine alongside an electric motor for propulsion. A small high-voltage battery powers the electric motor.

The first ever hybrid car was built by Ferdinand Porsche in 1899. The name may be familiar, as the engineer was also the founder of the automotive brand Porsche AG.

However, it was Toyota's launch of the Prius in 2010 that saw the term 'hybrid' become popularised and synonymous with vehicles. By 2014, hybrid cars had become a mainstay in the UK automotive market.

Typically, most hybrid cars in the UK will combine a petrol combustion engine with an electric motor. Diesel hybrids do exist, and Mercedes-Benz produces a number of them. However, diesel hybrids are more commonly found in large locomotive trains or other heavy-duty vehicles or machinery as opposed to everyday motorcars.

How does a hybrid car work?

Like a traditional car, hybrids are powered by a petrol or diesel engine and one or more electric motors. In turn, the two power sources can either work together or independently to help the car function.

In most hybrid vehicles, you have controls which switch between power modes depending on road and driving conditions to achieve optimal efficiency.

The combination of energy sources results in hybrids requiring less fuel to run. Ultimately, that means they produce lower exhaust emissions than traditional cars and can be cheaper to run.

Not all hybrids need to be plugged in to charge; some hybrids can self-charge their battery, either when driving at higher speeds or when slowing down using regenerative braking.

What is regenerative braking?

Self-charging hybrid cars use regenerative braking to allow them to recharge their batteries through braking power. The regenerative braking system is built into the hybrid car and to use it, the driver simply needs to take their foot off the accelerator to allow it to work.

In a hybrid car, the electric motor drives the wheels and powers the car. However, when you use regenerative braking, the motor stops powering the wheels and the car starts to naturally slow down.

At the same time, the electric motor will use the kinetic energy from the moving wheels to generate electricity and feed it back into the battery.

Different types of hybrid cars

There are three main types of hybrid car which all work in different ways to propel the vehicle:

• Mild hybrid electric vehicle (MHEV) - self-charging
• Full hybrid electric vehicle (FHEV/HEV) - self-charging
• Plug-in hybrid electric vehicle (PHEV)

What is a mild hybrid car (MHEV)?

Mild hybrid cars are powered by a battery-driven electric motor which assists the combustion engine. The electric motor offers limited electric assistance, less than in an FHEV or PHEV, making them more similar to petrol or diesel cars than other types of hybrid or fully electric cars.

This means that you cannot run an MHEV on the electric motor alone and you do not plug it in to charge. A mild hybrid car uses regenerative braking to charge the battery while you are driving.

Although electrical assistance from the battery is limited, it still reduces output from the traditional combustion engine, which can enhance fuel economy and boost acceleration.

MHEVs are available with both automatic and manual transmission.

What is a full hybrid car (FHEV/HEV)?

Self-charging or full hybrid cars can run solely on the electric motor, solely on the combustion engine, or a combination of the two - offering drivers three different ways to drive in one vehicle.

Like with all other hybrids, FHEVs work by combining an electric battery with a traditional combustion engine. The internal combustion engine (ICE) and regenerative braking recharge the battery, which means that you don't need to plug it in. Self-charging hybrid cars are usually only available with automatic transmission.

In an FHEV, drivers can use pure electric power for short distances at low speeds, in and around busy towns and cities for example, which will help save and minimise fuel efficiency. This system helps the engine to improve fuel efficiency, reduce CO2 emissions and engine noise as well as make the driving experience smoother.

What is a plug-in hybrid car?

Plug-in hybrid cars have larger electric batteries and have a longer electric-only range than FHEVs. PHEVs also use a combination of electric motor and combustion engine.

Regenerative braking will charge the PHEV while you are on the go. However, don't forget to plug in and charge this type of hybrid or you may end up relying solely on fuel power. These types of vehicles, once charged, should deliver between 20 and 30 miles of pure electric range before the petrol or diesel engine kicks in and takes over.

A PHEV can be a great alternative for those worried about range anxiety and not quite ready to make the switch to a fully electric vehicle. It's also worth noting that PHEVs are only offered with automatic transmission.

The benefits of hybrid cars

Some of the primary benefits of going hybrid include:

• Improved fuel efficiency - As a hybrid uses both electric and petrol or diesel power, they are more fuel efficient, meaning drivers can save money on fuel costs in the long run.
• Lower emissions - Better fuel efficiency usually correlates to a reduction in CO2 emissions. This is also appealing for those who want to help the environment or are worried about driving in or around Low Emission Zones (LEZs), Ultra Low Emission Zones (ULEZs) or Clean Air Zones (CAZs) in the UK.
• Range anxiety - Drivers may not be ready to make the full switch to electric due to 'range anxiety'. Owning a hybrid car can be the perfect introduction to those who want to make those first steps to electric. Having a mild or full hybrid car means drivers don't need to fully rely on electric power or charging their car and can still top up with petrol or diesel if needed.
• Driving performance - As a hybrid combines a petrol or diesel engine with an electric motor, more power is produced when driving, often resulting in enhanced engine output and performance.

Conclusion: are hybrid cars worth it?

If you are looking for a fuel-efficient, low-emission vehicle, a hybrid could be perfect for you. Hybrids are great for commuters taking daily short trips, especially as a PHEV will often be able to run solely on electric power for short journeys. This means you can rely on the electric mile range and save money on fuel.

Driving a hybrid car can also have other benefits, including lower road tax in the first year, lower company car tax, as well as possibly avoiding congestion charges and being able to drive in emission restriction zones.

Remember, whether a hybrid car is right for you is down to your individual driving needs, preferences, style and, most importantly, budget.

Your questions answered

At what speed do hybrid cars switch from battery power to petrol power?

It will depend on the make, model, trim, engine size and transmission you choose. Please do not hesitate to get in contact with one of our product geniuses who will be delighted to discuss specific model information with you.

Do hybrid cars need to be charged?

All hybrid cars need to be charged. It depends on which one you choose in terms of how it is charged. If you have a plug-in hybrid car, as suggested by the name, you will need to recharge it by plugging in.

How do you charge hybrid cars?

If you have a mild hybrid car or a full hybrid car, the internal combustion engine and regenerative braking technology charge the car on the go. If you have a plug-in hybrid car, you recharge it by plugging it in. To take full advantage of the electric mile range, a PHEV should be plugged in as often as possible.