It's all about saving you money
As a tyre rotates it deforms and dissipates energy. The energy that's lost is known as rolling resistance and this is what impacts on your fuel efficiency.
The lower a tyre's rolling resistance, the less fuel you will use and in turn your vehicle will create less CO2. Over a distance of 625 miles a vehicle with 'A' rated tyres will use 6 litres less fuel than a vehicle with 'G' rated tyres. So over the life of a tyre, the difference in fuel costs can really add up and have a real effect on the cost of your motoring.
Did you know?
20% OF A CAR'S FUEL CONSUMPTION IS INFLUENCED BY ITS TYRES.
With an average annual mileage of 12,000 miles, most Britons could look to save over 19 litres of fuel per tyre simply by upgrading one tyre by one grade. Each additional tyre label upgrade saves an additional 19+ litres of fuel so the savings changing from a G to an A grade tyre would be sixfold. That's something to think about in these tough economic times. It's all about fuel economy.
HOW DO TYRE MANUFACTURERS MEASURE THE GRADING?
Rolling resistance is measured by mounting the passenger car tyre on a two-metre drum and running it with a defined load and pressure. To rotate the drum without a tyre, a certain torque needs to be applied. The moment the tyre comes into contact with the drum, the torque required to rotate the drum needs to be increased.
By measuring the difference between the torque of the drum without the tyre and the increase when the tyre comes into contact with the drum it is possible to obtain a Rolling Resistance Coefficient (measured in kg/t). It’s this result that is used to define the specific grading on the label.
Tyre manufacturers are required to comply with the legislation, which means that you have reliable, objective and comparable data to help you chose the right tyre for you. The testing is:
- Self Certified
- Using EU-approved methods
- Enforced by local National Enforcement Authorities