Fuel economy labels for tyres

From 'The Road Ahead' (RACC)

While most people are familiar with energy star ratings on fridges and washing machines, and we are getting used to seeing them on cars, one day we may also have labels on tyres. Just as some appliances are cheaper to run than others, many people are unaware that the same goes for car tyres. Buying one tyre brand over another could potentially reduce the running costs of your car - the trouble is there is currently no way of knowing which tyres are more fuel efficient than others.

Now California has passed a law to develop and implement a Fuel Efficient Tyre Programme that boosts consumer information and sets minimum efficiency standards for tyres, which are due to be implemented by late 2009. And the European Commission is also set to introduce an energy labelling scheme for tyres, from 2011.

The key reason why some tyres are more efficient than others comes down to what is called 'rolling resistance'. Every time a wheel rotates, the weight of the car deforms the tyre as it makes contact with the road. The more the tyre deforms, the less efficient it becomes in moving the car forward.

The US National Academy of Sciences estimates that reducing the rolling resistance of car tyres by just 10 percent would cut American's fuel usage by 7.5 billion litres a year.