Decoding Your Tyre Sidewall Markings
That string of numbers and letters on the side of your tyre can look like a random code, but it tells you everything you need to know about your tyre's size, load capacity and speed rating. Understanding how to read a tyre sidewall means you can order the right replacement every time.
Breaking Down a Typical Tyre Code: 205/55 R16 91V
- 205 — Tyre width in millimetres (the measurement across the tread from sidewall to sidewall)
- 55 — Aspect ratio, the sidewall height as a percentage of the width (55% of 205mm = ~113mm sidewall)
- R — Radial construction (the most common type)
- 16 — Wheel diameter in inches (the size of rim the tyre fits)
- 91 — Load index. 91 = a maximum load of 615kg per tyre
- V — Speed rating. V = maximum speed of 240km/h (149mph)
Common Speed Ratings
- H = 210 km/h (130 mph)
- V = 240 km/h (149 mph)
- W = 270 km/h (168 mph)
- Y = 300 km/h (186 mph)
The DOT Code and Manufacturing Date
Look for "DOT" followed by a series of characters. The last four digits of the DOT code indicate the manufacture date: the first two digits are the week of the year and the second two are the year. For example, "2324" means the 23rd week of 2024. Tyres older than 7 years should be inspected professionally even if the tread appears fine, as the rubber compound degrades with age.