Incorrect air pressure, vehicle alignment, loose or worn parts, driving conditions, load, etc, can cause rapid or uneven tire wear. An accurate tread depth gauge can detect developing wear patterns earlier than simply looking at the tread. This often allows the cause to be identified and corrected before excessive or irregular tread wear ruins the tire.
Minimum tread depth should be 2.5mm or about 3/32. Any grove under this minimum depth is designated unsafe. The tire or tires should be replaced. At this depth, your vehicle’s tires will not adequately evacuate water and snow. The result is hydroplaning, sliding, and decrease braking efficiency.
While coins can be used to estimate remaining tread depth as a tire approaches the end of its useful life, the established method of measuring remaining tread depth in Canada is with a gauge that reads in millimeters (or in 32nds of an inch). Some tire tread depth gauges measure up to 25-26mm (or 32/32nds) since almost all passenger car and light truck tires begin with less than one inch of tread depth.
To use a tread depth gauge, follow the steps below.