An indication of tread wear is when the tread depth drops to approximately 1.6mm
*Circled areas are marked in color for explanatory purposes.
Relationship of tread depth and braking distance in wet road surface conditions
Tire size: 165SR13 radial rib / Initial braking speed: 80km/h / Road surface: Asphalt
Tires with a tread depth of 1.6mm or less are not allowed to be used as stipulated by laws and regulations.
When the tread is worn down ...
The brakes are likely to become less effective on wet roads!
When the tread depth drops below roughly 50% of new tires, the brake performance of tires on wet roads will gradually decline and the braking distance increases significantly.
Driving at high speeds in the rain is particularly dangerous!
When the tread depth decreases, drainage capability declines and it is more likely to cause slippage in rainy weather. Aquaplaning tends to occur and diminish steering and brake effectiveness especially when driving at high speeds.