Over time, it is normal for the tread on tires to wear. Checking the tread depth and wear on each tire will let you know when the tire needs to be replaced, or if other regular maintenance should be involved get the most out of your tires and vehicle.
As tires lose their tire tread, they also lose their ability to grip the road, which can cause the driver to lose control of the vehicle. Proper tire tread is crucial as precipitation escapes or compresses through the tread’s grooves to maintain as much contact with the road surface as possible.
In the United States, tire tread is measured in 32nd of an inch. Most all-season passenger vehicle tires are 9/32 to 11/32- in. In most states, 2/32-in. is the minimum tread depth requirement, which means, by law, drivers are required to replace a tire when a tire wears down to that depth.
Measuring tire tread depth
The “Penny Test” – Place a penny with Lincoln’s head upside-down in between the grooves of the tread between the tread ribs. If you see Lincoln’s entire head, it means you should replace the tire.
Tire tread wear bars – Within the tread grooves are tire tread wear bars so you can visually see if you’ve reached 2/32-in. If the tread ribs show the indicator bars, it means the tire should be replaced.
Tire Tread Depth Gauge – It is important for customers to purchase a tire tread depth gauge and to track their tire tread at least once a month. However, shops should use a professional tire tread depth gauge with the most accurate measurements and proper calibration.
Why should shops use professional tire tread depth gauge?
Tires are a significant investment for customers. Shops should educate their customers on why their tires are being replaced, possibly prematurely, to build a trusting relationship and create a repeat customer for years to come. Tires are one of the most important aspects of a vehicle and maintaining proper tire tread depth can increase a vehicle’s fuel efficiency and increase the overall value of the tire.
Some professional tire tread depth gauges allow information to be printed, stored or transferred to keep for repeat customers. All of these advantages using a professional tire tread depth gauge can bring opportunities for an increase in tire and TPMS services during routine tire maintenance.
There are many causes for tire failure on a road, and shops should educate their customers on the top causes for tire tread wear.
• Underinflated tires. According to NHTSA, having low tire pressure is the leading cause of tire failure. A professional tire tread depth gauge will typically indicate more wear on the outer and inner areas of a tire and less wear on the center area of a tire. The United States requires all passenger vehicles since 2008 to be equipped with TPMS, so it is important if a TPMS indicator shows low tire pressure, to get the tire checked. In addition, it is recommended that tires should be checked at least once a month to ensure proper inflation.
• Overinflated tires. It is a common misconception that adding more air in tires is best since most tires lose about 2 percent of their air pressure each month. However, overinflated tires can be just as dangerous as underinflated tires because it can cause premature tire wear on the center area of the tire and increase the chance of tire failure.
• Tire/wheel alignment issues. Improper alignment can cause tires to wear prematurely and unevenly. A professional tire tread depth gauge can measure if there is possible out-of-spec tire alignment wear due to alignment issues. For example, if the inner area of the tire wears faster than the outer area, this usually indicates misalignment, which could also indicate worn ball joints, sagging springs or other issues.
• Mismatched tires. Using worn tires with new tires or tires from different manufacturers can increase the chance of premature wear. A professional tire tread depth gauge can quickly identify mismatched tires, and unbeknownst to most, a difference as small as 4/32-inch between two tires can cause tire tread to wear faster.