Tread depth
You should also check the tread depth of your tyres; the minimum legal limit is 1.6mm across the middle 75% of the tyre at any point.Tyre wear indicators are located in the base of the tyre tread groove and act as minimum wear indicators. Once the tyre tread has worn down to these indicators, which are set at 1.6mm, your tyres are illegal.
Ideally, we would recommend that you change your tyres when they reach 3mm tread depth, as tyres below the 3mm recommendation are worn by up to 78% and will greatly affect the overall braking and cornering performance of your vehicle.
Tyres below a tread depth of 3mm are also affected by an increased risk of Aquaplaning when driving on wet roads. This is when a wedge of water is formed between the road and the tyre and means that the tyre loses contact completely with the road surface, so that neither the car's steering or brakes can be properly applied.
| Tread depth remaining | Wear rate % | |
| 8mm | 0% worn | |
| 7mm | 15% worn | |
| 6mm | 31% worn | |
| 5mm | 47% worn | |
| 4mm | 62% worn | |
| 3mm | 78% worn | |
| 2mm | 94% worn | |
| 1.6mm | 100% worn |
Legal issues
Remember that if your tyre is un-roadworthy you risk the performance of your vehicle and could also risk a possible maximum penalty fine of £10,000 and 12 penalty points on your driving licence.
| Number of faulty tyres | Maximum fine £ | Penalty points |
| 1 | £2,500 | 3 |
| 2 | £5,000 | 6 |
| 3 | £7,500 | 9 |
| 4 | £10,000 | 12 |
