There’s no doubting the rise in interest and popularity in electric vehicles (EVs) across the UK. In the space of less than five years, hundreds of new EVs of varying styles and capabilities have launched in this country.
And this is just the start. As the public charging point infrastructure improves, more new houses are built with charge points and more businesses switch to electric power for their vehicles, the sheer numbers of EVs driving on our roads will continue to accelerate.
But what if you’re still not convinced? Is there something holding you back? The initial cost? The anxiety of maybe running out of power before reaching your destination? The lack of a charging point at home, or no driveway to park your car off-road overnight?
Or maybe you just don’t really understand the whole topic of EVs and need more information and confidence?
You’re not alone. Thousands of drivers are yet to be convinced that now is the time to switch over permanently to an electric car – maybe for one of the reasons above. But they understand the ‘green’ issue of pollution and cars and want to do their bit to help cut down on CO2. It’s a dilemma.
But there is a solution worth considering – the hybrid.
What is a hybrid?
As well as the pure electric cars available now, many caar companies also offer various forms of hybrids. They are cars that have more than one power source – a combustion engine (usually petrol, occasionally diesel) and an electric motor.
Hybrids come in various forms with different names and badging, which can be unhelpful. But, in each case, the electric motor supports the combustion engine in some way, which keeps fuel consumption down and reduces exhaust emissions.
In some cars, the engine simply gets a ‘helping hand’ from the electric motor while, in other cases, the engine shuts down completely and the electric motor powers the car for a period of time.
Some hybrids don’t allow you to charge the battery from mains electricity, while others do (plug-in hybrids, hence the name). A plug-in hybrid will have a bigger battery and can go further on electrical power alone.
All forms of hybrid can use power from the petrol engine to charge the battery for the electric motor as needed. This is usually backed up with extra charging coming from regenerative braking – when you are coasting or braking, kinetic energy from the wheels turning isn’t needed to keep the car accelerating, so it’s converted into electricity to be stored in the battery. It’s like getting a but of free electricity every time you touch the brake pedal.
Best of both worlds
Clever electronics manage the use of both petrol and electrical power to make sure you’re getting the best combination of performance and economy, depending on what you need.
This balancing of fossil fuel and electricity means that your car tends to be working at its most efficient level more of the time than an ordinary petrol or diesel car.
If you’re bombing along a motorway at 70mph, the petrol engine is in charge because the electric motor would empty its battery very quickly. If you’re in morning traffic, stopping and starting and waiting endlessly for the lights to change, the electric motor can operates for more efficiently then a petrol engine.
Under full acceleration, the electric motor works together with the petrol engine to give better performance. You effectively have two power sources combining to deliver better performance than an equivalent petrol or diesel car could produce on its own.
And when you’re coasting downhill without even needing to touch the accelerator, the engine switches off and the electric motor is in charge, so there’s no fuel use at all. This, of course, is the primary attraction of a pure electric vehicle.
Assuming you have enough electricity in the battery, the electric motor can power the car when you’re pottering around and not demanding much acceleration. So if you’re driving around town in stop-start traffic or taking relatively short journeys, your petrol engine may remain switched off for a lot of the time.
And, of course, you don’t have to worry about running out of electricity because the car will simply switch over to petrol power once the battery is empty.
Worst of both worlds
Of course, it’s not all upsides. There are disadvantages to hybrids as well, which (funnily enough) don’t get mentioned in glossy car brochures.
Having two separate power sources in the same car means extra cost, extra weight, extra space and extra complexity. As well as having a petrol or diesel engine (plus gearbox, fuel tank, exhaust system, and everything else that a normal car has), you also have an electric motor (plus battery, equipment to convert energy to electricity, and additional electronics that control the petrol engine and electric motor working either together or separately).
All of this stuff costs money, so a hybrid car is more expensive than a regular petrol car. It’s also a lot of extra stuff to fit inside the car, which usually means that you get less boot space and sometimes less rear cabin space. And the extra weight means using more fuel or electricity to lug it all around.
If you’re battery has run flat, which will happen quite regularly for most owners, then you’re driving around in a petrol car that’s carrying a few hundred kilograms of useless electrical equipment. That means you’re using more fuel than if you had a normal petrol car.
Conversely, if you’re running on electricity, you’re lumping around hundreds of kilograms of idle petrol equipment. That means you’re not going as far on your battery as you would in a normal electric car. So both power sources are compromised by having to carry the other.
Also, if you’ve ever read car reviews of hybrid models, you’ll have probably noticed journalists moaning about the automatic transmissions that hybrids use. A hybrid or plug-in hybrid doesn’t work with a manual gearbox, and usually requires a specific type of automatic transmission called a continually variable transmission (CVT).
We’re not going to bore you with details, but basically they’re very efficient but not very enjoyable to use. If you like driving (like most motoring journalists), they’re not a lot of fun. If you don’t care and you’re just wanting to get from A to B, enjoy the fuel savings.
What are the different types of hybrid?
A mild hybrid is basically a petrol or diesel car with a minimal amount of assistance from a very small electric motor. This is the ‘helper’ set-up described above, and it’s rather a stretch to even call it a hybrid at all.
A mild hybrid car uses a very small lithium-ion battery to store the kinetic energy normally lost during braking or deceleration and sends it to a powerful starter motor and generator which helps the petrol engine pull away from rest and accelerate with improved speed, smoothness and economy.
Most mild hybrids can’t run on electricity alone, which means that your petrol or diesel will always be running to drive the wheels. There are a few exceptions, which can use electricity to power the car at very low speeds, such as crawling in heavy traffic. But this will literally exhaust the battery in a few metres, not a few miles.
In reality, a mild hybrid offers hardly any fuel savings over a normal petrol or diesel engine in real-world use. Its main benefit is to help generate improved fuel figures in laboratory testing, which makes the official fuel consumption figures look good but doesn’t carry over to most real driving situations.
The good news is that, because the electric motor isn’t driving the wheels, you can have a mild hybrid car with a conventional manual gearbox or any kind of automatic transmission, rather than the specific CVT automatics that proper hybrids use.
Pro: You can still have a manual gearbox
Con: minimal fuel savings
Want to know more? What is a mild hybrid? The Car Expert explains
The traditional hybrid has been around for more than 20 years now, most famously associated with the Toyota Prius but now available across models from dozens of car brands. There are a few diesel-electric hybrids around, but the vast majority are petrol-electric combinations, because a petrol engine is much better suited to being regularly switched on and off.
As described earlier, you have a full petrol engine setup plus a full electric car setup in the same car, with both units able to work together or separately as required.
Car company marketing departments often refer to these cars as ‘self-charging hybrids’, but this is absolute marketing nonsense and unhelpful to anyone trying to understand how they really work. A battery cannot charge itself, at least not in this universe.
You can’t plug one of these hybrids into a wall, so all of the battery charge ultimately comes from petrol power. Yes, it can be charged by coasting and braking, but ultimately you need the petrol engine to get you up to speed in the first place, so you’re really just recouping some of the energy you’ve previously used from the petrol engine. Ultimately, 100% of the electricity in a hybrid car originates from petrol. That’s not a criticism, just an attempt to deflate the marketing propaganda.
While the total range of a hybrid car in ‘electric’ mode is quite small, you can certainly get a few miles around town using only electricity. An electric motor is much more efficient than any petrol engine, so a hybrid can offer significant fuel savings in the right conditions. Which brings us to Nissan’s latest piece of hybrid tech…
The Nissan e-Power system is a different kind of hybrid. Nissan prefers not to describe it as a hybrid as well, because it’s essentially a petrol-powered electric vehicle. It has a petrol engine, but this is simply a generator for the battery. All of the drive is handled by the electric motor. We’ll cover this in reviews of the latest X-Trail e-Power and Qashqai e-Power models very soon, but it’s a much simpler and smarter way to combine a petrol engine and electric motor.
Pro: potentially good fuel savings
Con: technology pushes up the list price
The plug-in hybrid is the ‘most electric’ form of hybrid you can buy. Again, these are mostly a combination of petrol engine and electric motor, rather than diesel-electric. And, as the name suggests, you can plug them into an external charger to take electricity from the grid rather than purely by burning fossil fuels. The industry acronym is PHEV (plug-in hybrid electric vehicle), although most of them still spend more time as petrol cars than electric ones.
A plug-in hybrid have a large on-board battery which will store enough power to drive a reasonable distance in EV mode, with a range that’s usually somewhere between 20 and 50 miles. The electric motor is usually more powerful than you’ll find in a regular hybrid, meaning that it can cope with more demanding driving without having to wake up the petrol engine.
For many drivers this will be enough to get them to work and back (especially as more workplaces are installing their own charging facilities for this very reason). But because the battery is still relatively small compared to a dedicated EV, you need to charge it a lot more often. For most owners, this means plugging it in every day rather than every few days or even weekly like a full EV.
A petrol or diesel engine is also there to take over when the battery runs out. This is a great source of comfort for drivers who are not ready for the ‘range anxiety’ yet and can head off on a long motorway trek without worrying about running out of fuel.
Although they seem like the ‘best’ kind of hybrid, given that they maximise their electrical side and can be charged externally, plug-in hybrid sales have been tanking over the last year. That’s partly a supply issue, but also because many customers are either jumping over them to a full EV or holding back with a regular hybrid that is closer to a conventional petrol car.
Pro: Electric motor is used much more often, giving much better overall fuel economy
Con: They’re usually not cheap, plus you need to charge them regularly to get any real benefit
Additional reporting by Stuart Masson.