What is a hybrid car? Should you buy one in 2019?

Published: 30 April 2019

► CAR magazine guide to hybrid cars
► All about PHEVs and hybrids 
► Tech explained, jargon debunked 

Hybrid cars are partially electrified vehicles that still use an internal combustion engine; whether it's to drive the wheels or just charge the battery. Unlike an EV or BEV (battery electric vehicle) hybrids also have a petrol or diesel engine to fall back on if the electricity supply is dwindling. 

That makes hybrids a stepping stone to full EVs, and also means they're cleaner than standard ICE cars, but with more range and peace of mind than a standard EV. Simply put, they're a bridge between the fossil-fuel age and the new era of electrification. Buy one if you want to reduce your CO2 emissions, save fuel, dodge congestion charges and potentially lower your tax bills.

In this article we explain the major types of hybrid car on sale in 2019 and explain what types of hybrid car you can actually purchase right now. What's the difference between a mild hybrid and a PHEV? Keep reading to find out.

Further hybrid reading

The three different types of hybrid car in 2019

Hybrid cars have been around for two decades in series production: Japanese manufacturers have led the charge, and the Honda Insight and Toyota Prius were both launched within months of each other in the late 1990s. How influential these early pioneers have proven to be...

Hybrid cars come in all shapes and sizes

What is a full hybrid car?

A full hybrid is a car which can drive under its own electric power, petrol or a combination: an electric motor onboard is capable of driving the wheels under full e-power for a short distance, although most of the time the car will be driven by a mixture of combustion engine and electric motion. They are sometimes called 'parallel hybrids'.

Examples of full or parallel hybrids include cars like the Toyota Prius and the BMW 330e. Their batteries are typically small-capacity and they’re optimised for mixed running in daily driving, rather than extended zero-emissions electric range.

What is a mild hybrid car?

A mild hybrid car is one which cannot drive under electric power alone; the electric part of the powertrain is only used as assistance, and as a way to sometimes cut emissions.

However, some manufacturers also use the phrase to denote energy-saving systems designed to cut the engine at standstill and harvest power during deceleration. The Suzuki Swift 1.0 Boosterjet SHVS is one example of this: it can never run on electric power alone and its wheels are never turned by an e-motor, but its drivetrain does use electric-powered fuel-saving tech to reduce consumption. Mild hybrid is often also used to refer to a stop-start system, cutting the combustion engine at lights to save fuel.

What is a plug-in hybrid car (PHEV)?

A plug-in hybrid is often also referred to as a PHEV, standing for Plug-in Hybrid Electric Vehicle. The name even makes it on to the side of the car sometimes - see the Mitsubishi Outlander PHEV, for example.

Electric cars: hybrids are a stepping stone to full electrification (Getty)

In a delightfully Ronseal fashion, a plug-in hybrid does exactly what it says on the tin: you can plug it in to charge up the batteries when you’re at home or on a long journey (just like an electric car, above). This means you can provisionally start every journey with a full battery, maximising your chances of driving into city centres on silent and zero-emissions EV mode. 

Examples of PHEVs include the BMW i8 and VW Golf GTE. They typically have bigger battery capacities to enable their longer electric range (typically around 20-30 miles today). However, recent studies have proved that many owners treat them as internal combustion engine cars, never charging them up. This is a really bad idea, as you have to carry all the weight of those batteries, but without the benefits in effiency they can bring. The result? Sky-high bills and fuel economy worse than a petrol or diesel car!

That's what we found when analysing the running costs of our hybrid long-termers, too. 

What is a range-extender or REX hybrid car?

Yep, yet another category of hybrid… REX stands for Range-Extender electric vehicle, meaning the internal combustion engine onboard is only ever used as a generator to charge the battery of an EV, rather than to drive the wheels. The BMW i3 REX (below), Vauxhall Ampera and Chevrolet Volt are good examples of the genre.

BMW i3 REX plug-in hybrid electric vehicle (PHEV)

These range-extenders are also sometimes called a series hybrid (so named because the electric motor always drives the wheels - the internal combustion engine (ICE) is plumbed straight into the electric drivetrain, rather than the wheels on the road.

How does a hybrid car work?

As you can see from the above, the level of complication in a hybrid electric car varies hugely. All but the most basic mild hybrids have electric motors to drive the wheels and an extra battery pack to power the e-motors.Hybrid cars typically juggle power from electric and internal combustion engines

The clever bit comes in the power control electronics, which juggle the different power sources. Most do this quite seamlessly, so the driver merely steers, stops and goes - there are rarely other buttons to confuse things (apart from an EV button on some full hybrids, to select full electric drive around town).

The majority of hybrids are automatics, so you don’t have to change gear. You’ll usually find a Continuously Variable Transmission (CVT) gearbox, designed to maximise economy and deliver torque or pulling power when you need to accelerate fast.

So how do I charge a hybrid car?

Most hybrids are charged automatically without any intervention by the driver. Regenerative braking uses energy wasted during braking or coasting to recharge the battery, with lots of little micro top-ups during normal driving. Toyota has even started calling its models ‘self-charging hybrids’ to convey this to buyers.

The exception to this rule is a PHEV, which can be plugged into an electric plug to top up the battery: this can be done either at an EV charging point for faster charging or a domestic three-point plug if you’ve got time for a slow trickle charge. 

Our guide to UK electric car charging infrastructure

Hybrid cars for sale

Browse a mix of hybrids for sale in our classifieds listings here. Secondhand hybrid cars have proved popular with minicab drivers and other urban dwellers, suggesting that fears over the longevity of batteries is unfounded.

Should I buy a hybrid car?

Motorists looking to reduce their running costs should consider a petrol-electric or diesel-electric car; if going the full hog and picking an all-electric car is unrealistic for drivers doing longer distances, a hybrid could be just the stepping stone car you need.

Further electric car reading

The best electric cars and EVs on sale in 2019

How much does it cost to charge an electric car?

The best hybrids, plug-ins and PHEVs

Wireless electric car charging

By CAR's road test team

Our reviewers: fresh perspectives for inquisitive minds