Tyre Size Code

In 205/55 R16, 205 is the width in mm, 55 is the sidewall height as a percentage of width, R means radial and 16 is the rim diameter in inches. The numbers and letter after it are the load index and speed rating. The sidewall also shows the production date as a four-digit DOT code: the first two digits are the week, the last two the year.

The code allows you to choose a tyre that fits the rim and meets the car's requirements.

Fitting a different size can affect the speedometer, ABS and stability systems. Permitted sizes are in the owner's manual or on the door label. Tyres age even when unused; many manufacturers recommend checking or replacing tyres older than a certain number of years.