Your tires form the essential bond between your vehicle and the ground. The tread grips the road as you drive. But if it's not deep enough, your car loses traction and suffers extended braking times. Shallow tread grooves make it harder to control the vehicle in wet weather and the chance of aquaplaning increases. To ensure your safety, measure the tread depth as part of your regular vehicle maintenance.
Tread is the rubber on the tire that touches the road. New tires have an average tread depth of 8 to 9 millimeters (10/32 to 11/32 inches). As you drive, the tread will wear down. A tire with a tread depth below 1.6 millimeters (2/32 inches) lacks grip. Braking distance and vehicle control are impaired. These tires are not safe for driving and must be replaced.
Please consider that safe driving in wet and snowy weather conditions is affected by the tread depth, the pattern design and the rubber compound of the tread of your tires. On wet or snow-covered roads braking performance will progressively decline with lower tread depths. On wet roads there is an additional increased risk of aquaplaning with fading tread depths.
Therefore, check your tires regularly, reduce your speed on wet and snowy roads and consider replacing your tires in good time.
Ensure your vehicle is equipped with the correct winter, summer, or all-season tires.
Tread wear indicators, or wear bars, are spaced evenly through the main grooves in the tire tread. If they are flush with the level of the tread, then the tire should be replaced.
Several winter tire models are equipped with winter tire wear indicators. If they are flush with the level of the tread, the tire is no longer suitable for winter driving conditions. In some locations, they may also no longer legally qualify as winter tires.
If you have a tire tread depth gauge, use it to measure the tread depth. Insert the probe bar into the groove and push the shoulders flush with the tread. Check the top of the gauge to see the measurement. Alternately, a small ruler can be used.
Be sure to check in various locations. A misaligned wheel may result in uneven treadwear. Keep an eye open for any areas that look more worn than the surrounding surface. The tire's tread should be judged by the lowest depth you measured.
If you are uncertain of the measurements, take your vehicle to a service center.
While measuring the tread, look for cupping, or scalloping. These are small scoops, or divots, carved from the tread. They can indicate misalignment or other problems with your vehicle. Take your car to a service center.
Also, watch out for bulges in the tire tread or sidewall. They are not safe. You need to get a new tire.