Hybrid cars: a guide
Hybrid cars are at the centre of a green car revolution. As fuel prices rise at an astronomical rate and the world searches for alternatives to fossil fuels, hybrid cars have emerged at the head of the pack as the most realistic alternative to conventional powered vehicles. So what makes hybrid cars such a good alternative, how do they work and who are they right for?
We explain all in this guide to hybrid cars.
What is a hybrid car?
Broadly speaking, a hybrid car is one that uses two or more power sources, in reality it has come to mean a car which has an electric motor and a conventional engine (either petrol or diesel).
Technically, the most common form of hybrid car uses an on-board rechargeable energy storage system (RESS) and a fuel powered source to gain propulsion – these are known as hybrid electric vehicles (HEVs).
Generally, and for the purposes of this guide, we will refer to hybrid cars in their most common form – HEVs.
How do hybrid cars work?
Hybrid vehicles have existed in various forms for years – the moped is one of the most common examples as it combines a petrol engine with pedal power. Many locomotives also utilise both diesel and electric power, so the examples of hybrid vehicles are far and wide.
However, hybrid cars have been developed with the purpose of reducing CO2 emissions of cars. There are different types of hybrids; including diesel hybrids, range-extended electric vehicles, series hybrids, parallel hybrids and plug-in hybrids:
- Micro-hybrid drive - also known as start-stop function. It is a popular addition to most conventionally fuelled cars. This essentially switches off the engine when the car is stationary, i.e. when waiting at traffic lights. Although it is sometimes known as a micro-hybrid it does not use full hybrid technology.
- Parallel hybrids – Where the wheels are powered by the engine, by the battery-powered electric motor, or a combination of the two. These are the most common form of hybrid car at the moment, the electric motor is used, in the main, to reduce load on the combustion engine and in certain situations can operate purely in electric mode.
- Series hybrids – Utilise a combustion engine which generates electricity and powers an electric motor. The electric motor is always used to power the wheels.
- Mild and Full hybrids – terms used to denote the level of support the electric motor can provide to the combustion engine. Mild hybrids generally just use the electric motor to reduce load, while full hybrids can power the wheels in electric mode in certain conditions.
- Plug-in hybrid electric vehicles (PHEVs) – A hybrid car with a larger battery pack that can be recharged from an external electricity source. Plug-in hybrids run on battery power for the first 10-60 miles (16-100km) with the petrol engine only used when faster acceleration is required. They are considered a good alternative to electric cars which have a limited range because plug-in hybrids revert to the petrol engine when the battery is nearly discharged – or you can go to a charging station.
- Diesel hybrids - Can work like any of the above three, the difference is that until recently most hybrids were petrol powered, but as diesel gives greater miles to the gallon, the potential appeal of diesel hybrid is phenomenal.
- Range-extended electric vehicles (REEVs)- Like hybrids they combine a combustion engine and an electric motor. The difference is that ‘range-extended’ electric vehicles will use the stored energy in the on-board battery first until it is depleted rather than switching between electric and combustion engine depending on the speed of the vehicle. Once the battery is depleted the engine is used as a power source for the electric motor. Similar in many ways to Plug-in hybrid cars, a REEV can be plugged into an external power source to recharge the on-board battery.
Most hybrid cars also use a regenerative braking system. This system captures the kinetic energy generated when braking and ‘tops up’ the battery. This effective system can reduce overall fuel consumption by 20 per cent. Read on for more about regenerative braking.
What are the advantages of hybrid cars?
- Fuel efficient – generally speaking hybrid cars are more fuel efficient than conventional powered cars.
- Low CO2 – hybrid cars also emit less CO2 when looking at a comparable alternative.
- Lower Tax – thanks to lower CO2 emissions hybrid cars will generally be found in lower VED tax bands.
- Driving habits don’t change – living with a hybrid car is the same as driving a conventional car; visits to the petrol station will remain (but should become less frequent) and drivers do not suffer from ‘range anxiety’. Most hybrids cars also have conventional servicing patterns.
As Hybrid cars combine electric power with a conventional engine, it leads to a reduction in harmful emissions and so helps fight global warming. On European roads it has been estimated that petrol-hybrids can cut greenhouse gas emissions by around 25 per cent per mile. In the case of a vehicle such as the Toyota Auris Hybrid, which has CO2 emissions of around 89g/km, lifecycle carbon emissions are actually slashed to half those of a traditional conventional car.
Indeed hybrid cars are advantageous in their reduction of all harmful emissions: hydrocarbons, carbon monoxide and nitrogen oxides can be reduced by as much as 90 per cent.
Whether you have an environmental conscious or not, hybrid cars appeal to anyone who wants to save money – with statistics in the USA showing that the Chevrolet Volt can achieve approximately 60 miles to the gallon, doubling what is achievable in a conventional vehicle. With fuel prices reaching 135p/litre in the UK and $4/gallon in the USA, there are huge savings to be made over the lifetime of the vehicle.
Another advantage hybrid cars have is that they are ahead of other green car alternatives. Though electric cars, cars using biofuels, and vehicles powered by hydrogen fuel cells are emerging and may even be ‘greener’ than hybrids in the long term, they are all flawed in some way. Electric cars currently have limited range, biofuels are controversial because of the way they are produced and hydrogen fuel cells are a currently limited technology yet to be mass-produced. By comparison, hybrid cars are ‘ready to go’ in that they meet the demand of today’s society without compromise.
What are the disadvantages of hybrid cars?
- Still uses an internal combustion engine – the hybrid car is a step along the road to carbon free personal transport, not the end destination.
- Heavier – a hybrid car not only houses an internal combustion engine but also need an electric motor and battery pack(s), this adds weight and eats into space. While technology has resulted in battery and motor downsizing, some hybrids still have smaller cabins or loadspace than conventional cars.
- Expensive – a hybrid car has a higher on-the-road price than a comparable conventional car.
Although hybrid cars reduce CO2 emissions greatly, they are less useful over continuous high speed driving, such as on a motorway where emission levels will increase. A hybrid car still uses to a greater or lesser extent a conventional engine, therefore compared to alternative power sources – such as hydrogen fuel cell or electric – a hybrid car is not as green.
There are also concerns over the environmental impact of the hybrid car battery which is usually made from either nickel metal hydride or lithium-ion. Both are considered more environmentally friendly than lead batteries, but nickel-based batteries are known as carcinogens and there are concerns about the health problems they can cause though this is still the subject of much research.
Plug-in hybrids also face issues of their own in that a good, cheap battery pack is required. If everyone plugged into the utility grid at the same time the combustion problems caused by petrol and diesel cars would simply be displaced by the surge in use of generally coal-powered electric generating plants. Therefore it is hoped that cars can be charged late at night to create more efficiency and that initial generation can be made from renewable sources such as wind, hydro and tide power.
However, perhaps the biggest issue with hybrid cars is that they are generally more expensive than conventional cars and the initial retail price can be off-putting. Though money can be saved over the lifetime of the vehicle, a large initial outlay is still required and this puts hybrids out of reach for many drivers.
Why have hybrid cars earned celebrity status?
Hybrid cars are sometimes referred to as the ‘car of the stars’ thanks to their incredible popularity in Hollywood. Cameron Diaz was the first to publicly announce her support of the vehicles and regularly drives a Toyota Prius. Indeed many A-list celebrities have followed her lead including Tom Hanks, Jack Black, Larry David, Harrison Ford, Woody Harrelson and Kurt Russell. Leonardo Di Caprio was also famously quoted as saying that his hybrid car is just like any other vehicle except that he only has to fill it up once every three weeks.
What is it like to own a hybrid car? How much do hybrid cars cost?
As mentioned in the ‘disadvantages of hybrid cars’, they are typically more expensive than conventional vehicles – you can expect to add around £1,000-£2,000 on to the typical retail price of a £14,000 model depending on its hybrid design.
Hybrid cars are refuelled in exactly the same way as conventional cars and therefore you can use any normal petrol station. This lack of a technical barrier means that hybrid cars could soon emerge as the ‘norm’ across the UK and replace standard petrol and diesel vehicles.
Aside from the huge reduction in fuel costs, typically 15-30 per cent less fuel per mile, there are other savings to enjoy. For example, if you live in the London area, most hybrid cars are exempt from the London Congestion Charge (vehicle registration required). Nevertheless with so much to be saved on a daily basis, this exemption alone could save around £2,000 a year if central London is a regular destination. For more information and to check if your car qualifies for exemption, visit the Transport for London website.
You will also save money by being placed in a lower tax band – typically hybrid cars fit into the tax bands A-C. If your car emits less than 100g/km of CO2 it will be exempt from taxation altogether. By contrast, a car in the highest tax band could be charged more than £400 a year.
The cost of repairs is still a question with hybrid cars. It may be necessary to go to a specialist centre, although as hybrid cars become more common this should be less of an issue.
What hybrid cars are available?
The number of hybrid cars available in the UK is on the increase although they are still not as readily available as it is hoped they will be in the long term. Here is a list of some of the hybrid cars currently available in the UK – click on the links to find out more:
There are also several hybrid cars available in other markets:
Here is a list of some of the hybrid cars that are expected to come soon:
Forthcoming range-extended vehicles:)
How do I get a hybrid car?
Getting hold of a hybrid car is becoming easier as more models emerge – this increase in competition drives down retail prices. As hybrid cars first appeared in the UK in 2000, there are also some that are available on the used-car market with several Toyota Prius models even appearing on eBay.
If you are interested in leasing a hybrid car, ContractHireAndLeasing.com has the largest choice of car deals in the UK.
Paul Lucas - 2nd June 2008
Last updated: September 2012
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