Tread groove bottom (corresponding to the shoulder portion TWI) weeks to have at least four wear indicator. The standard specified that miniature and light truck tire tread wear indicator of the depth of is not less than 1.6 mm, truck tire tread wear indicator the depth of not less than 2.0 mm, if the groove depth is equal to or lower than the ground to wear signs, we advice replace the tires. Tire wear indicator is in the raised groove when the tread worn down to the wear mark, it flush with the tread and you are not wrong.

If you are using the remaining groove depth less than wear indicator that will appear the situation of rain tire traction and braking force suddenly losing, and no possibility of snow traction.If you replace the tire before it wears to wear indicator, it should not have these problems. In snowy areas, the tire wear will be replaced before this limit is also a wise move. In deep snow, the tire tread surface should be compacted and  have the ability to throw the snow.