1 July, 2021
Like it or not, electrification of our cars is here to stay, and hybrid cars are leading the charge.
Hybrids are often considered the stepping stone between cars with conventional internal combustion engines and pure electric vehicles (EV). Hybrids essentially combine the two.
But there are a few different types of hybrids, so to help you understand the options and the pros and cons of each, we’ve looked at some of the reasons you might consider a hybrid and explained how the different types of hybrids work.
What are the benefits of a hybrid car versus a normal petrol or diesel car?
Reduced running costs:
Hybrids consume less fuel than regular cars, since the electric motor drives the wheels for part of the time, especially from standstill or at lower speeds, and helps for the rest of the journey. When the engine fires up, it doesn’t have to work as hard either, as the car is already in motion, further improving fuel economy.
Lower tailpipe emissions:
In EV-only mode, there are no harmful emissions from the exhaust pipes, making hybrids especially suitable in densely populated areas.
Quieter, smoother operation:
Electric motors are almost completely noiseless and thus quieter than an engine, as well as smoother in operation, improving comfort.
The addition of an electric motor provides a useful extra amount of power and torque, for stronger acceleration and throttle response.
What are the advantages of a hybrid car versus a full electric car?
Cheaper to buy:
Using the Hyundai Ioniq as an example, the Elite Hybrid is less than half the price at $38,974 compared to its electric-only equivalent at $54,415. There’s also a plug-in hybrid version of the Ioniq available, and pricing for that sits in the middle at $47,040.
No range anxiety:
With hybrids able to use their internal combustion engines to keep the batteries topped up, drivers don’t need to worry about where their next charge is coming from.
No waiting for the battery pack to recharge:
EVs need time to fully recharge, from around 30 minutes at a high-capacity charging station to 24 hours or more using a household power socket, depending on battery size.
No parking to charge up:
Hybrids don’t need to be parked and plugged in to recharge, instead the on-board engine generates most of the electricity it needs.
How do hybrid cars work?
All hybrid cars use a clever combination of an internal combustion engine (usually petrol) and one or more electric motors to drive the wheels. The most common type of hybrid is the non-plug-in hybrid vehicle like a Toyota Camry Hybrid.
Next most common is the plug-in hybrid (PHEV), which has a larger battery that can be recharged using electricity from an external source like a household socket. Both have an engine paired with an electric motor, battery pack and generator, to send drive separately or concurrently to the wheels.
Third is a mild hybrid, which, as the name suggests utilises only a small amount of electric assistance. While mild hybrid vehicles have their internal combustion engine running all the time while driving, they do derive some fuel economy benefits from electric assistance.
There are also range extender hybrids, which are rare in Australia. We’ve explained these at item 4, below.
1. Hybrid Electric Vehicle (HEV)
In a series-parallel HEV, the battery pack is relatively small. It provides enough charge to get the car moving to speeds and distances of around 40km/h and 2km respectively, before the engine fires up to assist with directly driving the wheels.
The HEV’s battery pack is charged by the engine when driving, either when idling or on the move, and/or via kinetic energy gathered from the action of braking. This is known as regenerative braking. No external charging of the battery pack is possible, so don’t bother about looking for a wall plug or charging station. Note that Toyota promotes its hybrids as ‘self-charging’, which is technically true, but sidesteps the fact that a fossil fuel is still required for it to happen.
The PHEV, meanwhile, has a much larger battery pack, offering up to about 50km of pure EV range, before the engine takes over. However, while the PHEV’s battery pack is also charged as per the HEV’s, plugging into mains power is necessary due to its extra size and capacity. That’s the price you pay for having useable everyday pure-electric range.
Some older HEVs, like Honda’s defunct Insight, Civic Hybrid and CR-Z used a ‘parallel-only’ hybrid set-up, where the electric motor assisted the petrol engine but never drove the wheels directly. The 2020 Honda Accord Hybrid employs a ‘series-parallel’ arrangement similar to Toyota’s.
The benefits of HEVs:
Accessibility. HEVs are the cheapest entry into vehicle electrification, with prices for the Toyota Corolla Hybrid starting from $31,000 drive away.
Packs a punch. The available performance comes on strongly because electric motors produce their maximum torque from zero revs, boosting acceleration and providing immediate throttle responses. This in turn means a smaller-capacity and lighter petrol engine is sufficient, further improving efficiency.
Greener machines. HEVs produce fewer carbon and nitrogen oxide emissions than petrol or diesel cars, resulting in dramatically more economical and cleaner vehicles – especially in city areas where heavy traffic means the electric motor is more likely to be the main propulsion system driving the wheels.
Efficiency. All HEVs feature a stop-start function that cuts the engine when coasting at lower speeds and when braking. This further saves fuel, lowers emissions and cuts noise pollution. Sitting in heavy traffic is (slightly) more bearable with no idling engine droning away.
Refuel and forget. The very nature of the HEV – an electric motor and engine combo – means the battery pack never needs to be plugged into an external power source for recharging. The engine diverts power to a generator to charge it instead, or electricity is converted from otherwise wasted kinetic energy using regenerative braking technology. If you live in an apartment or have no access to off-street parking, you never need to worry about finding a long-enough power cord.
Result? No range anxiety or wasting time and energy finding a place to plug the car in, the HEV is great for city driving and short distance commutes.
The disadvantages of HEVs:
Expense. While there are cheap HEVs, they are generally more expensive than their equivalently-sized and equipped petrol-engined counterparts because of the added cost and complexity of electrification, from the battery pack and electric motor to the unique transmission and electrical cabling.
Not so great outside the city. HEVs are at their best in terms of driving performance and efficiency around town, because they can take advantage of the low-speed torque of the electric motor in stop-start traffic. Out on the open road at speed, they generally lose their economy advantages over petrol-only cars as petrol engines become more economical at cruising speeds but still have to carry the weight of the battery and electric motor. Basically, highway-only driving doesn’t properly leverage an HEV’s potential, and what you’re left with is a car with two propulsion units instead of one to lug around.
Less luggage space. Batteries are heavy and usually located in the lower rear half of a vehicle, at the cost of some luggage capacity, and usually with a temporary spare tyre instead of a full-sized spare. Some only have a tyre-inflator kit.
More to go wrong. Having two propulsion systems in the one car adds cost and complexity to servicing and repairs, though most have proven reliable and durable as electric motors comprise fewer moving parts and fluids than a petrol engine.
Battery cell degradation. Although battery packs are usually guaranteed for eight years, over time their ability to hold charge does decline. In hybrids, this means the petrol engine will run slightly more often than when the car was new. However, even with the battery beyond its best, the hybrid system will still have benefits over a petrol-only vehicle. Unless there is a major fault with the battery in its first three years, usually it becomes uneconomic to replace the battery in an aging hybrid.
Shock and awe. HEVs pose an additional safety risk to emergency services workers who must be specially trained to deal with the dangers of high-voltage hardware when attending an accident scene.
HEVs: The players
Credit where it is due. You cannot talk HEVs without starting with Toyota.
Since 2001, Toyota has offered the regular Prius, and from 2012 its hybrid range was bolstered with the Prius C city car for $25,000, which has now been replaced by the Yaris Hybrid. Toyota also launched the Prius V seven-seater wagon in 2012, though that is due to be discontinued in 2021.
Toyota has continued to introduce hybrid versions of many of its popular models.
These include the Camry Hybrid (since 2012), the Corolla Hybrid (from 2018), C-HR and RAV4 Hybrids (from 2019), Yaris and Yaris Cross Hybrids (2020) and the Kluger Hybrid (in the second half of 2021).
This strategy followed Toyota’s luxury brand Lexus’ lead back in 2003 with the RX premium medium SUV, with most models following suit since. It is also likely that Australia’s bestselling vehicle, the Toyota HiLux truck, will eventually go HEV.
Toyota/Lexus aside, only five circa-$50,000 HEVs currently exist – the Hyundai Ioniq Hybrid, Subaru’s XV and Forester E-Boxer, the Kia Niro Hybrid and the Honda Accord Hybrid.
2. Plug-in hybrid electric vehicle (PHEV)
As the name suggests, a PHEV is a hybrid but with a socket like an EV, so it can be charged from an external source, such as from a home, office or charging station. In normal driving, some electricity is fed back into the battery pack from the engine and regenerative braking systems within the car, however the plug-in capability provides the option to charge the PHEV’s battery (which is usually larger than a regular hybrid’s battery) from an external power source, allowing for longer electric-only range.
Some PHEVs can be made to use their petrol engine to fully charge the battery while being driven, however this is not a very efficient way to charge the battery.
With an externally chargeable battery, a PHEV is much closer to the ownership and driving experience of an EV.
Compared to its hybrid sibling, the Hyundai Ioniq PHEV’s battery is more than five times the capacity. Think of the battery-pack as a fuel tank for electricity, so the bigger it is, the further you can travel. In plug-in hybrids, in EV mode the use of the electric motor is prioritised until the battery is depleted, after which the car works more like a regular hybrid, with petrol engine and electric motor working together more frequently for propulsion and to keep a minimum charge in the battery.
It’s the solution to range anxiety while still enjoying many of the EV advantages. You’ll just need to charge a PHEV more often than a fully electric car in order to keep running on electricity.
Some PHEVs have a phenomenal combined petrol/EV range, such as the $120,000 Mercedes-Benz E300e’s theoretical 2700km distance between refills. Though to do that, you’ll need to stop every 50km or so to recharge the battery.
As with all EVs, a PHEV comes with its own charging hardware, namely a cable to a three-pin household socket. Additionally, a wall box can be purchased, installed by an outside supplier from around $3000.
The advantages of a plug-in hybrid:
Got your back. As with EVs, PHEV owners report that they habitually plug their cars in to charge overnight as they would a mobile phone, except they don’t worry about being left stranded if they occasionally forget to recharge their cars.
Saves money. US studies have shown that using household electricity to charge a PHEV costs substantially less than the fuel a HEV requires to recharge their (much smaller) battery packs – though PHEVs usually cost a lot more to buy in the first place.
Save more money. A PHEV’s low fuel consumption and emissions ratings would come in handy if Australia switches to a European-style emissions-based registration and taxation system, further rewarding EV and PHEV motoring.
Choice. PHEVs allow the driver to control when the electric motor operates, to preserve charge for when it is most beneficial running in EV mode, such as in built-up areas or during traffic jams.
Not just around town. EV charging infrastructure is growing rapidly across Australia, meaning PHEV owners are increasingly able to use their vehicles without the engine security blanket if they so desire.
How’s the serenity. In EV mode, PHEVs are as hushed and smooth as EVs, while packing plenty of low-down torque oomph.
Price shock. PHEVs are cheaper than EVs. Using the Hyundai Ioniq as an example, the plug-in model is $7,300 less than its electric counterpart.
The disadvantages of a plug-in hybrid:
Even more to go wrong. The added complexity of a larger and heavier battery pack, combined with extra electrical engineering for the plug-in technology, means more to service and repair over the longer term, on top of the engine and motor combination.
Scarcity. Currently there are few PHEVs to choose from.
Purchase price. PHEVs cost substantially more than their petrol and HEV counterparts – around $8,000 is the additional premium you’ll pay to get the Hyundai Ioniq PHEV over the regular Ioniq Hybrid.
Less luggage space. As with most HEVs, PHEVs powertrain electrification often results in reduced cargo capacity, though it’s worse in the PHEV because the battery pack is larger again, often necessitating the removal of a spare wheel.
Battery costs. Though a warranty for up to eight years is the norm, if you do choose to replace a PHEV’s battery pack, it’ll be more expensive than an HEV’s smaller equivalent. For example, a Prius battery pack is about $4000 while an PHEV’s can cost upwards of $15,000 (before labour) for some models, so you’ll need to consider whether this sort of expenditure makes good economic sense in an older vehicle.
Charging inconvenience. Using a regular household outlet requires around six to eight hours depending on the PHEV, while obviously a HEV requires no plugging-in hassles.
Charge it or lose it. Owners who forget or don’t bother to plug their cars in and drive their PHEVs purely on petrol will suffer higher fuel consumption compared to regular cars and especially HEVs.
PHEVs: The players
Mitsubishi’s Outlander PHEV (from $47,390) paved the way for mainstream PHEVs when it arrived in 2013. Blending SUV practicality with a 50km EV range has helped it become history’s best-selling PHEV.
Among the cheapest are the Hyundai Ioniq Plug-in (from $47,040), Kia Niro PHEV ($49,990) and Ford Escape ST-Line PHEV ($59,305).
From there up it’s mostly all premium, from the BMW 330e, Mercedes-Benz C300e and Volvo S60/V60 T8 PHEVs at under $100K, to luxury limos at more than twice that amount such as the BMW 745e and Porsche Panamera 4E-Hybrid.
Notable PHEV SUVs include the Mini Countryman, Volvo’s XC40, XC60 and XC90 T8s, the Mercedes GLC 300e, BMW X5 45e, Range Rover/Range Rover Sport and Cayenne E-Hybrid, while Ferrari’s SF90 Stradale tops out at a cool $850K.
3. Mild hybrids
Mild hybrids commonly have an engine starter motor that can also function as an electricity generator (known as a starter-generator), so after starting the engine, the same unit can also send energy back into the car’s battery, which is usually a 48-volt unit rather than 12 volts.
This removes the need for a conventional alternator and separate starter motor, saving weight, and brings the ability to give the petrol engine a boost under acceleration. Mild hybrids with starter-generators also commonly include engine start/stop technology, which operates far more smoothly than start/stop systems in cars with conventional starter motors.
Mild hybrid cars currently for sale in Australia include the Mazda3 Skyactiv-x and MX-30, the Mercedes-Benz C 200 and the Audi A4.
4. Range extender hybrids
Range-extender (or REx) hybrids only have an electric motor driving the wheels, but they carry an on-board small petrol engine that is there solely as an electricity generator to recharge the battery pack.
The Holden Volt (2011-2014) and BMW i3 REx (2014-2019) are defunct examples. Both were well packaged and good to drive but short on range and too expensive, with the latter was also criticised for providing disappointing additional extended petrol range, while being markedly noisy when the extender engine was running.
No range-extender hybrid is currently sold new in Australia, though Mazda has indicated it may introduce one in 2022.
Hybrid cars FAQs
Which is better – a HEV or PHEV?
Hybrid on a budget, PHEV for that all-electric experience but with a petrol engine back-up for extended journeys and no range anxiety.
Are hybrids worth it?
If using considerably less fuel and creating fewer emissions are important to you, then definitely. Hybrids are usually more affordable than full electric cars, and often more responsive to drive than their petrol-only equivalents.
What are some of the disadvantages of a hybrid/plug-in hybrid?
They cost more to buy, and may cost more to service. They sometimes weigh more so might be slightly more expensive to register here in WA due to a car’s mass affecting rego costs, and they often have reduced luggage and/or seating space, and might not have a full-sized spare tyre.
Do plug-in hybrids charge while you drive?
Yes, they ‘self-charge’ in that the petrol engine sends power to charge the battery pack, while energy from braking is captured and stored as electricity. Some PHEVs can also charge the battery all the way up while driving. You can also then choose to run in petrol/electric hybrid mode and save the charged battery for later.
What plug-in hybrid has the longest range?
Luxury carmaker BMW offers the 330e PHEV with an all-electric range of more than 60km, while Mercedes-Benz claims its E300e PHEV can go up to 2,800km combining both the battery range and 60-litre petrol tank. However, to achieve that you’ll need to be very diligent with recharging the battery, which may not be practical on long journeys.
Can you drive a plug-in hybrid without charging?
Yes, just as you would a normal-engined car, but the extra weight of the electric bits would mean it would use more fuel than a non-PHEV equivalent.
What happens if you don’t charge a plug-in hybrid?
Nothing, it will still drive normally, except you won’t enjoy any pure-electric driving range.
Can hybrid cars run on fuel only?
Yes. HEVs rely on fuel to run as their all-electric range is only about 2km before the petrol engine kicks in. The petrol engine will start running earlier if you’re going up a hill or accelerating hard. Plug-in models can go up to about 40-50km in most cases before their engine chimes in to assist.
What happens when a hybrid car runs out of battery power?
Nothing, it’s business as usual, as the engine kicks in to assist with driving the wheels and recharging the battery pack.
Choosing a hybrid for your next car? We'll reward you
Our Less Emissions Mission program rewards owners of lower emissions vehicles with discounts of up to 25% on comprehensive car insurance, discounted rates with RAC Finance and savings on RAC Auto Services.