Tyre size and performance markings are printed on the sidewall and follow a standardised format. A typical example is:
385/65 R22.5 160K
- 385 – The tyre width in millimetres.
- 65 – The aspect ratio: the sidewall height is 65% of the tyre’s width.
- R – Radial construction.
- 22.5 – The wheel rim diameter, in inches, that the tyre fits.
- 160 – The load index, indicating the maximum weight the tyre can safely carry. Refer to an approved load index chart for exact load values.
- K – The speed rating, representing the maximum sustained speed the tyre can handle under load. Refer to a recognised speed rating chart for specific limits.
Other sidewall markings may include manufacturing dates, ply ratings, rotation direction, and indicators such as 'TL' (tubeless).
Frequently Asked Questions
What does the load index number mean on an HGV tyre?
The load index is a code that corresponds to the maximum weight a tyre can carry at a specified inflation pressure. Fleet operators should consult an approved load index table when determining compatibility.
What does the speed rating letter represent?
The speed rating shows the maximum sustained speed the tyre is certified to handle under load. Each rating, such as J, K or L, corresponds to an exact km/h limit within official reference charts.
How can I identify the tyre’s manufacturing date?
Manufacturing dates are indicated by the DOT code on the sidewall. The final four digits show the production week and year, for example '3423' for week 34 of 2023.
What does 'TL' mean on a tyre sidewall?
'TL' indicates that the tyre is tubeless. This marking helps operators confirm compatibility with their wheel and inflation systems.
