Since the dawn of motoring we’ve only had one sure way of comparing tyres – and that was price, writes Nick Gibbs.
But in November 2012 the tyre industry gave us three new ways to compare rubber – measuring an individual tyre’s performance in terms of wet grip, noise levels and rolling resistance.
New labelling to show the results of these tests was developed. These labels resemble the ones you see on fridges and washing machines, rating performance on a simple colour-coded A to G scale. But are they worth reading?
New tyre labels help improve your car’s fuel economy, safety and comfort
Tyres account for 20-30 percent of our fuel consumption. Okay, there’s no such thing as a frictionless tyre, but with the right compound with very low rolling resistance you can improve your economy by seven percent using tyres given a top A rating instead of those rated G.
Wet grip adds a safety angle and measures the tyres’ ability to stop the car on a wet road.
The third measurement, expressed in sound waves (fewer the better) tells you how much noise they’ll make.
Tyre makers are responding to ratings
And the labelling is having another, perhaps less obvious benefit. It’s driving tyre manufacturers to produce ever better tyres.
Tyre data supplier Cam Systems report that more tyre makers are offering so-called double A tyres, meaning they score the prized A rating for both rolling resistance and wet grip.
That’s very hard to do, says Vanessa Guyll, technical specialist at the AA, because a tyre that stops you smartly in the wet is not the same as one that offers low rolling resistance. The trick is a new compound with lots of a synthetic material called neodymium polybutadiene rubber.
That increases the price, but not by as much as the £40 per tyre the AA first predicted it would. And hopefully, you’ll make that back in fuel savings. Research carried out by the University of Munich suggest that on average a family car travelling 20,000 a year would cut its fuel bills by £250 by switching to A-rated tyres.
But there are still unknowns: “We don’t know whether the compound will last,” says Guyll. So it could remove all those fuel savings by wearing out quicker. The AA also warns that there other variables to consider, for example dry road braking, wet road handling and comfort.
How YOU can make a difference…
Then there’s the huge difference we make to the tyre’s performance.
As we point out on the tyre advisory section of our website, a new tyre with its 8mm of tread depth will stop your car much more quickly than one with the legal limit of 1.6mm of tread left on.
And if you fail to pump them to their proper pressure, you will radically increase rolling resistance and wear while reducing braking performance.
Every type of Toyota service level from intermediate to a full service will check pressures and tread depth, which removes some of the worry about maintaining your tyres. Our service technicians also advise on issues outside of the label, for example whether a certain tyre will lasts a good amount of time before needing replacing.
Hopefully this labeling system will persuade more people that tyres are crucial to the efficient and safe performance of our cars.
But some things remain out of the control of both you and the tyre companies. Road surfaces can make a big difference to rolling resistance, and right now in spring, all the winter’s frost damage makes them rougher and therefore noisier.
And while we’re on the subject of weather, Finnish tyre expert Nokian says that water on the road a depth of just 0.5mm can increase rolling resistance by 50 percent. Put another way, mother nature imposes its own fuel tax, but at least now we can offset by reading the label. Now, partly at least, you can judge a tyre BEFORE you fit it to your car.