Tread depth and tread wear indicators

Fig. 172 Tread pattern: Wear indicator.

Read and follow the introductory information and safety information first⇒Introduction to the subject

Tread depth

Most driving situations require as much tread depth as possible and similar tread depth for the tires on the front and rear wheels. This is especially true when driving in winter weather, at low temperatures and under wet conditions ⇒ .

In most countries the legally permissible minimum tread depth is 1/16 in (1.6 mm), as measured in tread grooves next to the wear indicators. Please be sure to obey country-specific legal requirements.

Winter tires are no longer suitable for winter operation once the tread pattern is worn down to a depth of 3/16 in (4.8 mm).

The tread depth of new tires can differ between tire models and manufacturers because of the different design features and tread patterns.

Tread wear indicator (TWI) in the tire

The 1/16 in (1.6 mm) high wear indicators are molded into the bottom of the tread grooves of the original tires running across the treads ⇒ Fig. 172 . Several wear indicators are evenly spaced around the tire. Markings on the sides of the tires (for example “TWI” or symbols) show the position of the wear indicators.

Wear indicators show when the tires are worn down. The tires must be replaced no later than when the tread pattern is worn down to the wear indicators.

Worn tires are dangerous and can cause loss of vehicle control including serious personal injuries.

• Never drive a vehicle when the tread on any tire is worn down to the wear indicators, replace them sooner.

• Worn tires do not grip the road properly, especially on wet roads, increasing your risk of hydroplaning and loss of control.

• Worn tires reduce the ability of your vehicle to handle well in normal and difficult driving situations and increase braking distances and the risk of skidding.