READING A CAR OR CARAVAN TYRE

The side of your tyre is covered in numbers and letters, a kind of secret code describing its size, age and function

SIZE

You’ll see a number laid out on the side of the tyre. In this example, the tyre size is 205/55 R 16. Here, 205 denotes the width of the tyre in millimetres, as measured from shoulder to shoulder. The 55 displays the profile or aspect ratio of the tyre (the depth of the sidewall). This is expressed as a percentage of the width, so here, the depth of the tyre is 55% of its 205mm width. R shows that this tyre has a radial construction: the cord plies cross the tyre at 90° to the direction of travel, for added strength. Almost all new tyres are radial. The 16 shows the diameter of the wheel rim that the tyre is designed to fit, measured in inches.

RATINGS

Here, H denotes the speed rating, which is measured on a scale of A to Y. The H indicates a tyre rated to travel at up to 130mph. The top rating, Y, is 186mph-plus! The 91 is the tyre load index. This tyre can carry up to 615kg in weight; 92 is 630kg, 93 is 650kg, and so on.

DATE OF MANUFACTURE

This four-digit code displays the week and year that the tyre was made. For example, 1219 is the 12th week of 2019.

TYPE OF TYRE

Here the words ‘Tubeless’ and ‘Radial’ denote the type of tyre and its design/structure.

RUNFLAT TYRES

Tyres that maintain their shape and performance, even when deflated, are commonly found on modern cars, as manufacturers do away with spare wheels. Runflat tyres are very rigid, to the point that many think they spoil the ride, but if you do have a puncture, you can typically drive up to 50 miles at 50mph (although the slower the better). Runflats cost more than standard tyres and, of course, you need a pressure monitoring system, or you would never know if the tyre had deflated! I have yet to see them on a caravan (although they would make sense), but they seem to be standard on higher-end car brands.