Plug-in Hybrid versus Full Electric? Which one is right for you?

By the end of 2018, it is estimated that there will be around 200,000 plug-in hybrid (PHEV) or pure electric (EV) vehicles on the road in the UK. With virtually every major manufacturer now offering at least one PHEV or EV (or both) models, and government grants still available at present for home and workplace chargers to be installed at a heavily subsidised cost, more UK drivers are willing to dip their toe into the electric car market than ever before.

There are currently over 60 plug-in models of vehicle available in the UK, plus their variants, which offers a level of choice that can feel a little bewildering to those who are looking at getting their first electric vehicle. If you’re wondering whether to go all-in with a pure EV, or opt instead for a PHEV, this guide might help you to make up your mind.

The difference between hybrids, PHEVs, EVs & extended range EVs (EREVs)

When it comes to the fairly new world of EVs and hybrids, there’s already more jargon than you can shake a stick at. Any vehicle that has two different types of motor can be called a hybrid, so we have mild hybrids, full-hybrids and plug-in hybrids, as well as EVs and EREVs; understanding the differences between them will help to determine the best fit for your lifestyle and driving needs.

Mild hybrid cars have a regular petrol combustion engine as well as an electric battery, with the engine being the primary source of power and the car having the ability to charge its own battery when driving using the petrol engine. The electric power in this type of hybrid is not used to actually power the car’s motion, but instead to assist the engine, giving it additional power when accelerating, for example. It improves fuel economy but does not offer any zero emissions driving at all.

Full hybrids have a larger capacity battery and an electric motor that can power the vehicle alone over very short distances, and usually only at fairly low speeds e.g. busy city driving or in traffic jams. The combustion engine in a full hybrid car does most of the work, and will kick in as soon as the car speeds up or travels as far as the battery power can take it. The battery will then recharge itself for the next time the vehicle slows down or stops. Again, fuel economy is usually the main motivation for drivers buying this type of hybrid, as it only offers a small amount of zero emissions driving.

PHEVs are hybrids that have a larger battery alongside their petrol engine; too large a battery to be recharged by the engine and regenerative braking alone, so they need to be plugged in, hence the name. The larger battery gives the PHEV the ability to travel much further and faster than a full hybrid on the electric motor alone. The 100% electric powered range in a PHEV will vary, depending on the model of car, but is usually under 30 miles, at a max speed of 70mph, at which point the petrol engine will take over and the vehicle then acts in a similar way to a full hybrid. Not only making a huge difference to petrol economy, PHEVs also offer significantly more zero emission driving than full hybrids.

EREVs are essentially another type of plug-in hybrid, although the combustion engine plays a smaller part in the process than in other types of hybrid cars. The engine can’t actually drive the wheels, but is purely there to recharge the car’s battery when needed. It is the electric motor that actually powers the car’s motion. Until the battery runs low, this type of vehicle acts just like an EV. When the battery needs additional help, the small petrol engine kicks in to recharge it as you drive, extending the range before needing to plug in again. EREVs offer considerably more zero emissions driving than the other types of hybrid and can have an electric-only range of up to 125 miles, depending on the model. Therefore, shorter journeys could be completely powered by electricity alone.

EVs only have an electric motor and their single source of power is their battery pack; thus, they offer zero emission driving 100% of the time.

PHEVs & EVs compared

Range

A PHEV usually offers a much greater driving range than most comparable Pure EVs do, with their combination of power sources. Although the range does vary with different models, many PHEVs can achieve around 300-400 miles with both petrol and electric sources used. This is similar to many standard petrol-only cars, but PHEVs do give a significantly lower level of emissions.

With EVs, the 100% electric range in miles does vary considerably, depending on model and driving style, from the top of the range (and the budget) current Tesla Model X with 100kW battery, giving up to around 350 miles of driving on a single charge, to an electric SMART car or the Peugeot iOn, offering less than 100 miles before needing to recharge the battery.

Range anxiety is commonly cited as the main reason against more widespread adoption of EVs thus far, which could be why PHEVs are a less scary leap for many people wanting to move away from 100% combustion engine driving. However, research shows that with half of car journeys under 5 miles in distance and just 2% over a distance of 50 miles, easily within the capabilities of EVs, range is not something that most UK drivers would need to necessarily worry about.

Cost of purchase

As with any type of car, purchase price for PHEVs and EVs do vary considerably, depending on the manufacturer, model and spec options.

Some EVs have a compulsory monthly battery rental cost, and others have the cost of the battery included in the purchase price, so this is another consideration when it comes to cost.

New EVs start with entry level models OTR at around £18,500 for a Renault Zoe (plus battery hire), just over £25,000 for a new Nissan Leaf (battery included) and range up to the starting prices for Jaguar’s I-PACE (approx. £63,500) and Tesla’s Model S (from £66,730). High-spec versions of some of these EVs can cost around £130,000.

New PHEVs start at around £25,400 for a basic Hyundai Ionic, approx. £32,300 for the highly popular Mitsubishi Outlander, and at the higher end of the scale, the BMW i8 Coupe starts at over £112,700.

When compared to conventional petrol cars, the original purchase price of EVs and PHEVs may seem a little on the expensive side, even after a subsidy. The general thinking is that savings are made on running costs rather than on the initial purchase.

Cost of running

Once you have taken any battery lease costs into consideration, depending on the manufacturer and model you choose, the other ongoing costs, like fuel and maintenance, come into play. Pure EVs enjoy free VED (road tax), whereas any other type of car, including PHEVs, will need to pay at least £130 per year for this.

Charging costs will vary, depending on the battery size in the vehicle and the source of the electricity (i.e. home charger, public charger), but we have worked out basic cost comparison of some popular EVs and PHEVs.

With PHEVs, however, you also need to consider the cost of running the petrol engine alongside the electric motor unless it’s being used only as an EV. These costs will vary, depending on the petrol tank size and engine efficiency. For PHEV drivers who rarely charge their electric battery and mainly rely on the combustion engine, any efficiencies will be minimised.

When it comes to car maintenance, such as annual servicing, EVs are generally considered to be cheaper, as there are less components to go wrong. Currently, virtually all mechanics trained in working on EVs are part of the main dealer networks, which means that EV owners have less choice about who can work on their vehicle than conventional petrol/diesel car owners. However, as EVs become increasingly popular, independent and chain mechanics are expected to get themselves up to speed and qualified for working on electric cars sooner, rather than later.

Servicing costs for PHEVs can actually be higher than conventional combustion engine cars and EVs, as they have both a petrol engine and an electric motor and battery to service. This will boil down to individual dealer servicing tariffs.

Deciding on the right option for you – EV vs PHEV

Whether to go with a pure EV or opt for a PHEV will depend mainly on how you intend to use the car and what your motivation is for moving away from the conventional combustion engine driving in the first place.

For those who do mostly short journeys around a town or city and want to make the best possible savings on running costs, as well as enjoy the principle of zero emissions driving, an EV seems the natural choice.

For those who perhaps drive long distances on a regular basis and are mainly motivated by improving fuel economy, a PHEV could be the better option, at this point in time. Those with range anxiety concerns may find PHEVs a less risky first step.

EV technology is moving incredibly quickly, so we don’t expect it will be too many years until pure EVs are capable of a range in miles to rival any current PHEV or conventional combustion engine vehicle.

Further Reading

• Our EV Facts and Figures page looks at running costs and emissions from electric vehicles
• Decided on your car?  Then you’ll need a chargepoint for your home.
• Still unsure?  We look at overcoming EV range anxiety