Vehicles also produce tailpipe emissions such as oxides of nitrogen (NOx), oxides of sulphur (SOx) and particulate emissions that affect air quality.

Although vehicle engines are becoming far cleaner and more efficient, the numbers of vehicles on our roads is increasing and we are using these vehicles far more.

The importance of driving efficient vehicles is clear when you consider that 85% of a typical vehicle's lifecycle CO2 emissions occur during its actual use.

The UK Government is under international and local pressures to reduce emissions from vehicles and has introduced a number of environmentally based taxation schemes to encourage the uptake of more efficient cars both for the private motorist and the company car driver.

The majority of these schemes are targeting vehicle CO2 emissions primarily to address the issue of global warming, however a vehicle's CO2 emission levels are directly proportional to its fuel economy. Hence by incentivising low CO2 emitting vehicles the Government is also promoting the most fuel efficient vehicles.

For a company operating a fleet of cars and/or light vans, or requiring employees to use their own cars for business use, this all results in a complex arena, where the costs of operating environmentally inefficient vehicles can be high.

Estimated lifetime CO2 emissions from a typical car. Source SMMT.