Tyre manufacturers have been working to develop new products that can deliver good performance in both rolling resistance and wet braking performance
Traditional tyre compounds cannot achieve the highest, 'A' label grades for both low rolling resistance and wet braking performance.
Wet braking performance was included on the new tyre label to try to ensure that the desired improvements in low rolling resistance were not achieved at the expense of safety.
Tyre manufacturers have been working to develop new products that can deliver good performance in both rolling resistance and wet braking performance.
Premium tyres now use high-performance synthetic rubbers designed to give tyres specific properties that enable them to reduce rolling resistance and the amount of fuel you need to use, without adversely affecting wet braking performance.
LANXESS – one of the companies responsible for making these advanced rubbers – has developed an online calculator that can help you understand the potential fuel savings to be made by replacing all four road tyres with premium tyres with an 'A' grade rating for rolling resistance.
The calculator is based on a set of formulae developed by the University of Munich as part of an independent research project carried out for LANXESS in 2011. the calculator shows that a family car covering 9,000 miles/year and averaging 30mpg could see as much as a £179 reduction in fuel bills* if all four road tyres were switched from budget tyres to tyres with an 'A' grade for rolling resistance.
The new label
When you drive, your cars’ tyres change shape to absorb changes in the road surface such as potholes, speed bumps, and dips. As the tyre changes shape to accommodate various surfaces, it dissipates lots of energy from the engine to the road in the form of heat.
Tyres with low rolling resistance lose very little of this energy so the engine does not need to work as hard to move the car forwards.
On average, 20-30% of fuel consumption is used to overcome rolling resistance in premium tyres. So every fourth visit to the pumps is for the tyres alone.
The reason that state-of-the-art tyres can offer better rolling resistance is down to the tyre’s chemical make-up.
Over 200 ingredients go into a car tyre, falling into three main categories:
These are mixed together to create up to 12 different rubber compounds that, when blended can be shaped into a tyre.
‘Greener’ tyres contain a high percentage of a very particular type of rubber called neodymium polybutadiene rubber. Specifically designed following many years of scientific research, its molecular structure means tyres containing this rubber retain much more energy and therefore use less fuel to travel the same distance.
Remember that you can also save fuel by following our simple eco-driving advice.
* Assuming a fuel price of £1.37/litre
(5 September 2012)