Tyre Markings Meaning
1. Tyre Sizes
The tyre size is composed of four numbers, such as 205/55/R18 105V, which indicate the tyre’s width, sidewall height, construction type, and wheel rim diameter.
- 205 – the tyre width in millimetres
- 55 – indicates the tyres sidewall height as a percentage e.g. 55% of the tyre width
- R – indicates that the tyre is of radial construction
- 18 – the wheel rim diameter measured in inches.
2. Mounting Direction
Asymmetric tyres have a specific indicator that shows which side of the tyre must face outward. Directional tyres have a marker to indicate the required direction of rotation.
3. Maximum Load and Pressure
Tyres have a maximum load capacity and pressure limit, which are detailed in your vehicle handbook.
4. Tyre Pattern Name
Each tyre pattern is designed for different purposes, so it is essential to recognize the different types.
5. Materials
Tyre sidewalls may include information about the materials used and how the tyre was manufactured.
6. European ECE Type Approval Marks and numbers
These marks indicate that the tyre has passed all European safety standards, and the ‘S’ symbol indicates that the tyre meets EC noise directives.
7. Load Index
The load index indicates the maximum load capacity a tyre can carry, and it appears before the speed index letter. For example, a tyre size of 205/55/R18 105V means the tyre can carry 925kg.
| Load Index | Kilograms | Load Index | Kilograms | Load Index | Kilograms |
|---|---|---|---|---|---|
| 65 | 290 | 80 | 450 | 95 | 690 |
| 66 | 300 | 81 | 462 | 96 | 710 |
| 67 | 307 | 82 | 475 | 97 | 730 |
| 68 | 315 | 83 | 487 | 98 | 750 |
| 69 | 325 | 84 | 500 | 99 | 775 |
| 70 | 335 | 85 | 515 | 100 | 800 |
| 71 | 345 | 86 | 530 | 101 | 825 |
| 72 | 355 | 87 | 545 | 102 | 850 |
| 73 | 365 | 88 | 560 | 103 | 875 |
| 74 | 375 | 89 | 580 | 104 | 900 |
| 75 | 387 | 900 | 600 | 105 | 925 |
| 76 | 400 | 91 | 615 | 106 | 950 |
| 77 | 412 | 92 | 630 | 107 | 975 |
| 78 | 425 | 93 | 650 | 108 | 1000 |
| 79 | 437 | 94 | 670 |
8. Speed Index
The speed index is the letter that follows the load index and indicates the maximum speed the tyre can handle.
| Speed Symbol | Approx MPH |
|---|---|
| Q | 99 |
| R | 106 |
| S | 112 |
| T | 118 |
| H | 131 |
| V | 149 |
| VR | 131 |
| W | 168 |
| Y | 186 |
| ZR | 149 |
9. Country of Manufacturer
Tyre markings can also inform you of the country where the tyre was made.
10. Tyre Brand
The manufacturer of the tyre is identified on the sidewall.
11. Tyre Wear Indicator
Tread wear indicators are added to some tyres, with a marker set at 1.6mm. When the tread wears down to the indicator, it’s time to replace the tyre by law.
