Electric and hybrid cars explained
Everything you wanted to know about hybrid, fully electric and fuel cell cars, but were afraid to ask, plus all the jargon explained...
Electric cars and hybrid cars are more popular than ever, and although it’s still a niche market, more than 500,000 such cars have been sold in the UK.
Sales have picked up dramatically this year, with more than 114,000 alternatively fuelled vehicles (AFVs) registered up to the end of September – up 21.7% on the same period last year.
But with the proliferation of these cars, so too has come a whole range of terms surrounding them. Here, we explain them in plain English.
Types of cars:
What is an alternatively fuelled vehicle (AFV)?
Any car that doesn’t solely use a conventional petrol or diesel engine falls under these umbrella terms.
What is an electric vehicle (EV)?
This term is used for cars that run solely on electricity and therefore produce no exhaust emissions, a leading example being the Kia e-Niro, our 2019 Electric Car of the Year. Also known as battery electric vehicles (BEVs), instead of a petrol or diesel engine, they have an electric motor that is powered by batteries, which you charge by plugging the car into a socket.
For: Zero-emissions running; far quieter on the road; much cheaper to refuel; EVs with a list price below £40,000 are exempt from road tax and the London Congestion Charge.
Against: Ranges have improved - the e-Niro has a real world range of 253 miles - but they still aren’t comparable with those of other types of car; long charging times; poor predicted residual values.
What is a hybrid?
A hybrid car combines a conventional petrol or diesel engine with an electric motor and batteries. Although not as ‘green’ as fully electric cars, hybrids generally consume less fuel and produce less CO2 than conventionally powered cars.
The most common type is the parallel hybrid – sometimes known as a self-charging hybrid – and is found in cars such as the Toyota Prius. The engine is still the main power source, but the wheels can be powered in three different ways: either directly by the engine, by the electric motor alone, or by both working together. You never need to charge these hybrids. Most can run on electric power only for just a few miles at low speeds.
For: They’re really economical for stop-start city driving, because the electric motor gets the most use and the regenerative braking boosts the batteries whenever you decelerate or use the brakes.
Against: Fuel economy tends to nosedive out of town, because the batteries make the car heavy and the electric motor will soon run out of charge at higher speeds and under hard acceleration.
What is a plug-in hybrid electric vehicle (PHEV)?
As the name implies, this type of hybrid can be plugged into an electric outlet to recharge its batteries, as well as being charged on the move. One of the most popular so far is the Mitsubishi Outlander PHEV.
In effect, it’s a halfway house between a parallel hybrid and a full electric vehicle. Although it has a conventional engine, it also has larger batteries than a parallel hybrid and can drive for longer distances and at much higher speeds on electric power alone – up to 30 miles and at least 70mph in some cases.
For: Has a longer range than an electric car; cheap to use for short, urban journeys that don’t deplete the batteries.
Against: Batteries add weight, making fuel economy poor on motorway runs once the batteries are depleted; need to recharge batteries more often than a pure EV, which will have a longer range; need to plug in to properly charge, unlike parallel hybrids.
What is a range extender?
These cars run on electricity but have a small petrol or diesel engine that is used to produce electricity to recharge the batteries and extend the car's range; it never powers the wheels. The aim of range extenders such as the BMW i3 REX (there’s also a fully electric version) is to provide an extra 70 to 100 miles of range once the batteries have been depleted, giving extra flexibility between charges.
For: Better than a parallel hybrid for longer, out-of-town journeys, because it drives on electricity only; no range anxiety, thanks to the engine.
Against: Extra weight of engine means the car isn’t very economical when it’s generating power, so the overall range will be less than that of a comparable regular electric car.
What is a hydrogen fuel cell vehicle?
These cars mix hydrogen with oxygen in a fuel cell to produce electricity. They’re rare – the Toyota Mirai being one of the few you can buy – because they’re expensive and there are fewer than 20 public hydrogen refuelling stations in the UK.
Hydrogen-powered cars take less than five minutes to fill up, have a greater range than battery-electric cars and only emit water from their exhausts.
They are therefore seen by some people as the best longterm solution to emissions-free driving. However, the processes used to generate and transport hydrogen make them less ec0-friendly overall than conventional electric cars at present.
For: Quick refuelling time; range between fill-ups is far closer to that of a petrol or diesel car, zero tailpipe emissions.
Against: Infrastructure is in its infancy; high CO2 emissions from current production process; technology is very expensive.
