Buying a greener car

14 February 2008

Green labelling

Similar to the energy labels on kitchen appliances, although still voluntary, these labels show how much carbon the vehicle produces, its fuel consumption, and your likely fuel costs over 12,000 miles.

Rated A-G (with A being the most efficient), the most efficient cars, such as the VW BlueMotion, emit less than 100g CO₂/km, while the worst will produce more than 185g CO₂/km. The Range Rover Freelander 1.8 petrol creates 248g CO₂/km.

Hybrid cars

Hybrids such as the Toyota Prius use a conventional petrol motor as well as an electric battery that charges as you drive and automatically switches on when the car slows down, making city driving (under 30 mph) much greener.

They cost around two-thirds less to run than a petrol vehicle and are exempt from London congestion charging. They also have a reduced road tax. But remember, they're not the answer to cutting transport emissions as they're only green when going slowly.

Electric cars

With no exhaust emissions, electric cars are currently the greenest and cheapest way to go (assuming your electricity supply comes from renewable sources). Plug them in, charge up for a few pence and away you go. Suitable only for urban or local driving, electric cars have a typical range of about 40-50 miles and a top speed of about 50 mph, but technology is improving fast.

In London and Manchester (other cities are on the way) you'll enjoy free parking permits in most boroughs, free access to central car parks, no congestion charge and free road tax. If your electricity supply comes from non-renewable sources, it has been estimated that electric cars run at the equivalent of about 70g CO₂/km.

Liquefied petroleum gas (LPG)

To get your car adapted to use LPG will cost £1000 - £2000, but it is more efficient than petrol and produces less pollutants than diesel. A full tank will cost around half the cost of petrol, although the cost of new LPG cars will be higher - typically £1200 - £2000 more than for non-LPG versions. In 2007 there were 223 LPG refuelling stations around the country.

Biofuels - too good to be true?

The cultivation of plants for biofuel is driving massive deforestation in South East Asia and also increasing competition and conflict over land, driving up food prices which will threaten the lives of some of the world's most vulnerable people. While the technology is undoubtedly greener at point of use, the knock-on effect could be disastrous and actually produce more greenhouse gases than it saves.

Petrol versus diesel?

Diesel cars are more fuel-efficient than petrol-driven ones - burning a litre of diesel creates more CO₂ than burning a litre of petrol, but the engine efficiency just about makes up for that. However, diesel will create more dirty emissions such as nitrogen oxides and particulates that can affect health.

If you are considering buying a diesel car, choose one with a diesel particulate filter (DPF), as this will reduce these emissions. That said, if you live in an urban area and drive a petrol engine that uses the latest low-sulphur fuel, it will be greener than diesel.

Top 5 carbon-friendly cars

1 G-Wiz (electric) 

carbon: 0 g/km (assuming you recharge using a renewable supply)
mpg: n/a
range: 48 miles before recharging
price: From £8,895

2 Volkswagen BlueMotion

carbon: 99 g/km
mpg: 74.3
price: £11,995

3 Mini Cooper D hatchback with particle filter

carbon: 104 g/km
mpg: 72
price: £14,000

4 Toyota Prius petrol hybrid fourdoor family car

carbon: 104 g/km
mpg: 65.7
price: £17,000 - £20,000

5 Citroen C2 1.4 diesel

carbon: 107 g/km
mpg: 61.4
price: £7,995

Buying second hand

Because green cars are relatively new, tracking down a second-hand green motor might be difficult. If you're looking for a secondhand car check out What Car? for detailed lists of every car make and model including the CO₂ emissions so you can be sure you're choosing the least polluting vehicle.

You can also buy a second hand G-Wiz from GoinGreen.

This article is based on an extract from Friends of the Earth's book How Can I Stop Climate Change?

Read more about getting the most out of car travel in Car sharing and car clubs