How to Check Your Tyre Tread Depth: The 20p Test Explained

Your tyre tread depth directly impacts your stopping distance and road safety. Learn the simple 20p coin test and know when it's time to replace your tyres.

Tyre tread depth is one of the most critical safety factors on any vehicle. In the UK, the legal minimum tread depth is 1.6mm across the central three-quarters of the tyre. Driving below this limit is illegal and extremely dangerous.

The 20p Coin Test

The easiest way to check your tyre tread depth is the 20p coin test: 1. Insert a 20p coin into the tread groove of your tyre. 2. If the outer band of the coin is hidden, your tread is above the legal limit. 3. If you can see the outer band, your tyres may be illegal and need replacing immediately.

Why Tread Depth Matters

Tread depth affects: - Wet weather braking — At 1.6mm vs 3mm, stopping distances can increase by up to 44% - Aquaplaning resistance — Deeper treads channel water away more effectively - Fuel efficiency — Worn tyres can increase rolling resistance

When Should You Replace Your Tyres?

Most tyre safety experts recommend replacing tyres at 3mm rather than waiting for the legal minimum of 1.6mm. The difference in braking distance between 1.6mm and 3mm in wet conditions is significant.

Book a free tyre inspection with Eddie's Mobile Tyres today.