Motorists will be able to fill their tanks with greener fuels when a new initiative comes into force in the UK this week.

The move is known as the Renewable Transport Fuel Obligation (RTFO) and requires 2.5% of all road fuels sold to come from biofuels, rising to 5% by 2010.

Motorists will fill their vehicles as normal, but the change is expected to save 2.5million tonnes of carbon dioxide by 2010.

It is part of a package of measures being taken to reduce the impact of transport on the environment.