I PUT new tyres on my Nissan X-Trail and managed only 15,000 miles before both sets needed changing. My garage says the usual wear and tear is only 18,000 miles. Why don’t consumers get a health warning on tyre wear, as we do for grip, fuel economy and so on? DC, Inverness
The information currently given for tyres consists of a grade for rolling resistance, which is the energy lost when a tyre is moving — the lower the rating, the better the fuel economy; wet grip; and noise levels. All of these are relatively easy to measure. But tyre wear is virtually impossible to predict, because there are so many variables. These include the style of driving, the speed travelled and the load the vehicle is carrying (aggressive cornering and acceleration, higher speeds and heavier loads all result in increased wear).
In addition, the type of driving you do is important: lots of motorway travel is easier on tyres than driving down twisty back-roads, because cornering makes tyres work harder and wear more quickly. Different road surfaces also affect tyre wear: smooth tarmac, clearly, is easier on tyres than a harsh, recently gritted road. If your driving includes many of these wear factors, a tyre life of 15,000 miles is not unusual.
That said, there is one simple step you can take to improve the life of your new tyres. Incorrect tyre pressure is one of the principal causes of excess wear, and it takes just a few minutes to correct. We suggest you buy a good-quality pressure gauge, because those found at garages are often inaccurate following the careless treatment they get from users. We’d recommend Halfords’ tyre pressure/tread gauge (£10, halfords.com). Your car’s manual will tell you the correct pressure.
Ideally, tyres should be changed when the tread depth reaches the 3mm mark. This is more than the legal limit of 1.6mm, but performance drops off massively between the two figures. Testing has shown that with the lowest level of legal tread it can take an additional 144ft — or around 10 car lengths — to stop at 70mph in the rain.
Dave Pollard has written several Haynes manuals and has tested just about every car-related accessory – read more from Dave here.
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