When it comes to checking tire tread, there are a number of methods that can help you know if it’s time to replace a tire. Heavily worn tread will prevent a tire from performing as designed and can lead to unsafe driving conditions. One of the simplest, most common ways to check tread depth requires nothing more than a coin and a few moments of your time.

Tire Tread Depth

In Thailand, tire tread depth is measured in millimetres (mm). New tires typically come with 7mm – 9mm tread depths, and some truck and SUV tires may have deeper tread depths than other models. The Land Transport Authority (LTA) legally requires tires to be replaced when they reach 1.6mm.

Therefore, it is important to maintain a minimum tread depth of 1.6mm for your tires.

Consistent wear around the whole tire is normal, but uneven tread wear could be a sign of improper inflation, wheel misalignment, or other problems. If you see uneven tread wear, you should have a qualified technician to inspect your vehicle.

Other Ways to Check Tire Tread

Tread Depth Gauge

A simple way to check your tire tread depth is by using a tread depth gauge. You can find tire tread depth gauges at your local workshops or accessories stores. There are many models available, but an inexpensive simple graduated probe gauge will work just fine. All you have to do is stick the probe into a groove in the tread and press the shoulders of the probe flat against the tread block and read the result. All gauges should measure in millimetres.

Tread Wear Indicator Bars

Another indicator of worn out tread already lives in your tires themselves. Every performance, light truck, or medium commercial tire comes equipped with indicator bars (or wear bars) embedded between the tread ribs at 1.6mm. They’re there to help you monitor tread depth and make decisions about tire replacement. Check if the tread is flushed with the indicator bars. If they are, it’s time to replace the tire.

Don't Wait Until It's Too Late

While the tread depth gauge does deliver on what it promises – indicating whether tread has reached the legal limit – it may not be the best indicator of whether your tires are safe for the road. Tire performance can diminish significantly before your tread hits 1.6mm. Even though the law deems fit for safe driving may not prevent you from hydroplaning or losing control in rainy, slushy conditions. If you think your tires may be close to needing replacement, have them checked out by a qualified technician for a peace of mind.