What is a hybrid car and should you buy one?

A hybrid car is one that uses more than one means of propulsion:  a petrol or diesel engine and an electric motor.

The main advantage of a hybrid is that it should consume less fuel and subsequently emit less CO2 than a comparable conventional petrol or diesel-engined vehicle.

Because hybrid cars often have lower CO2 emissions than conventionally engined cars, their owners may also get extra benefits in the shape of lower first year road tax and less costly company car tax, as well as possibly avoiding congestion charges.

How do hybrid cars work?

Hybrid cars have a conventional engine, an electric motor and a battery. There are three different types of hybrids and each works in a different way.

1. Parallel hybrid cars

These are the most common type of hybrid, and the now used-only Toyota Prius is the most widely known example. The car’s wheels can be powered in three different ways: directly by the engine, by the electric motor alone, or by both power sources working together.

When pulling away and at speeds up to 15mph, the Prius only uses the electric motor for power, making it very economical for stop-start city driving. The petrol engine cuts in as speed increases and is used most during hard acceleration.

Whenever you decelerate or use the brakes, a regenerative braking system produces electricity and stores it in the battery for use later on. The battery is small, though, so the electric motor can only power the car for up to 1.25 miles.

Toyota also uses its hybrid system in the Yaris and Corolla hatchbacks and C-HR and RAV-4 hybrid SUVs, and cars from its luxury brand Lexus work on the same basis.

2. Range extender hybrid cars

These only use their conventional engine to produce electricity for a generator that recharges the batteries. The engine never drives the car, it only produces energy for the electric motor.

The BMW i3 with Range Extender (now available only as a used car) is one of the most popular examples. The Honda Jazz, which is the What Car? Small Car of the Year 2023, also uses a pair of electric motors to help its conventional 1.5-litre petrol engine when required. The Jazz has three driving modes: EV, Hybrid and Engine. In the first, the petrol engines charges the battery, which powers an electric motor to drive the car. In Hybrid mode the car switches between using the petrol engine and electric motor to drive the car depending on the conditions. In Engine mode only the engine propels the wheels. 

Hybrids are also categorised as either strong or mild depending on the amount of battery power they have. With more battery capacity, strong hybrids can drive further than mild ones on electric power only.

3. Plug-in hybrids

As the name implies, this type of hybrid can be plugged into an electricity outlet to recharge its batteries, as well as being charged on the move.

Effectively, plug-in hybrids (PHEVs) are a halfway house between conventional hybrids and full electric vehicles. Although they have a conventional engine, they also have larger batteries than regular hybrids and can drive longer distances on electric power alone – up to 50 miles in some cases.

Our favourite PHEV is the Lexus NX 450h, which has an official electric range of 43 miles – 13 miles longer than the BMW X3 xDrive30e. If you can plug the NX in regularly and mostly do short journeys, you could achieve as much as 313mpg, because, when the batteries have run out, it still has fuel economy of close to 40mpg. 

What are the benefits of a hybrid car?

Driving a hybrid is similar to driving a conventional automatic car; you needn't worry about changing gear.

Most strong hybrids will have a choice of power modes, too, ranging from eco to power, enabling the driver to choose maximum efficiency or performance depending on the driving conditions.

Unlike pure electric cars, you'll have no concerns about running out of battery range because the combustion engine is always there when you need it. And, with a parallel hybrid, you don't need access to a charging point because it can charge its own batteries as you drive. You will need a handy charging point, though, if you want to make the best use of a plug-in hybrid's fully electric mode.

Although the tax benefits of hybrid ownership aren’t as great as they used to be, company car drivers still pay less benefit-in-kind (BIK) tax than drivers of petrol or diesel cars, and cars emitting less than 75g/km may be exempt from regional clean air zone or low emission zone charges.  

Should I buy a hybrid car?

A hybrid car will suit you if you do most of your mileage in and around town because you’ll gain the most benefit from running on electric-only power.

If you make frequent short trips and don’t need the extra flexibility of a hybrid, then you may be better off with an electric car, which will give you urban travel with no tailpipe emissions and no need to visit a filling station.

However, if you do a lot of motorway miles you may be better off with a mild hybrid or efficient diesel car, both of which are likely to provide better high-speed fuel economy than a hybrid. On motorways and fast A-roads, the speed at which you're travelling is likely to be beyond what a hybrid can sustain in its pure-electric mode over a long distance.

Next: Best hybrid cars 2023 >>

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