The Wheel And Tyre Bible
Check your tread depth
Bald, slick tyres might be good for motor racing but they’re no good on the road.
Most tyres come with tread wear bars built into them now – find one, examine it and if your tread is too low, replace your tyres.
Four new tyres might seem expensive but they’re cheaper than a fine or an accident.
Tread depth and tread wear indicators
A tyre tread wear indicator.
For the most part, motoring law in most countries determines that your tyres need a minimum tread depth to be legal.
This varies from country to country but is normally around 1.6mm. To assist you in figuring out when you’re getting close to that value, most tyres have tread wear indicators built into them.