CO2 Emissions

Buying a car based on CO2 emissions usually means going for a modern car with a small engine and lightweight construction. The most efficient cars are the cheapest to run and often have lower road tax and insurance rates.

Fuel is also a consideration - to really cut down on your CO2 emissions, you could consider buying a car capable of running on an alternative fuel such as biofuel, LGP or electricity (hybrid).

Of the standard fuels, diesel engines emit less CO2 per mile than petrol equivalents, although they do emit higher levels of particulates and nitrous oxides, which are bad for air quality.

The Government uses a colour-coded system to rate the emissions and level of road tax for new cars. Some Councils are also using this as a basis for parking and access charges like the congestion charge in London.

Newer cars

You can find information about a newer car's CO2 emissions from the following sources:

  • The environmental label which should be displayed on all new cars in showrooms. This grades each car from A (the cleanest) to G (the most polluting).
  • The Vehicle Certification Agency which has a database of cars with their fuel economy and CO2 emissions data available at www.vcacarfueldata.org.uk
  • In car adverts - manufacturers are obliged to publish CO2 emission information by law.

Older cars

It is more difficult to find out CO2 emissions for older cars. However, you may be able to find this information in your car handbook. Alternatively, The Society of Motor Manufacturers and Traders has a database of vehicle CO2 emissions going back as far as January 1997.

In summary, the general advice for people seeking a low CO2 car is to go for the smallest, simplest car possible, with the highest environmental rating. Newer cars tend to be more efficient than old, so consider upgrading regularly if you drive a lot (to ensure you are driving the most efficient model), less frequently if you don’t drive very often. Consider choosing a vehicle that can run on less polluting fuels.

Once you have your car, use it responsibility and appropriately as part of a range of transport options including walking, cycling, public transport and car sharing. Also see our page on Safe and Economical driving for advice on running your car efficiently.