HGV tyre sizes and performance markings are printed on the tyre sidewall using 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 width.
- R – Radial construction.
- 22.5 – The wheel rim diameter, in inches, that the tyre is designed to fit.
- 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.
Additional sidewall markings may include manufacturing dates, ply ratings, rotation direction and indicators such as 'TL' for tubeless tyres.
Frequently Asked Questions
What does the load index number mean on an HGV tyre?
The load index is a coded value that corresponds to the maximum weight a tyre can carry at a specified inflation pressure. Operators should consult an approved load index chart when checking tyre suitability.
What does the speed rating letter represent?
The speed rating identifies the maximum sustained speed the tyre is certified to handle under load. Ratings such as J, K and L each correspond to a specific km/h limit within official reference charts.
How can I identify the tyre's manufacturing date?
Manufacturing dates are shown within the DOT code on the tyre sidewall. The final four digits indicate the production week and year, for example '3423' means week 34 of 2023.
What does 'TL' mean on a tyre sidewall?
'TL' indicates that the tyre is tubeless. This marking helps confirm compatibility with the wheel and inflation system.
