How to check your tires
- Park on level ground with the tires cold. You need a tread depth gauge and a pressure gauge.
- Find the placard pressures on the driver’s door jamb, fuel flap or in the owner’s manual, and enter them.
- At each tire, measure the tread in a main groove near the inner edge, the centre and the outer edge. Read the four-digit DOT date code (see how to read a tire sidewall). Check the pressure and look for damage.
- Press Check tires for a per-tire summary, then add a monthly reminder to your calendar if you like.
Reading wear patterns
Comparing the inner, centre and outer readings shows how the tire is wearing. Tire makers commonly associate these patterns with the following causes, though a professional inspection is the way to confirm one:
- Centre worn more than both edges: often linked with running above the recommended pressure.
- Both edges worn more than the centre: often linked with running below the recommended pressure.
- One edge worn more than the other: often linked with wheel alignment.
Differences smaller than 1/32 in (about 0.8 mm) are treated as even, because that’s within the precision of most gauges.
The references used
- Wear bars at 1.6 mm (2/32 in): the depth at which tread wear indicators are moulded. It’s the legal minimum in the UK and EU; check your local rule.
- Placard pressure: your vehicle maker’s cold pressures. For context, US rules (FMVSS 138) require a tire pressure monitoring system to warn when a tire is 25% or more below the recommended pressure; that’s a warning level, not a target.
- Age: from the DOT date code and today’s date on your device. There’s no single age limit for every tire; check the vehicle and tire maker’s guidance.
- Projection: a straight-line estimate from tread when new, tread now and distance covered. Real wear isn’t perfectly linear.
Frequently asked questions
How do I measure tread depth?
Use a tread depth gauge in the main grooves, not on the wear bars. Take readings near the inner edge, in the centre and near the outer edge, and enter the lowest reading at each position. Gauges are cheap and far more accurate than coin tests.
What does the 1.6 mm figure mean?
Tread wear indicator bars are moulded into the grooves at 1.6 mm (2/32 in). When the tread is level with them, the tire has reached the wear-bar level, which is also the legal minimum in the UK and EU. Legal minimums differ elsewhere, and many drivers replace tires earlier; enter your own planning depth if you want results against it.
Should I check pressure hot or cold?
Cold, before driving more than a few miles. The placard pressures on the door jamb are cold pressures. Use the tire pressure converter if your gauge reads in different units.
Is any of this saved or sent anywhere?
No. The check runs in your browser. Nothing is stored unless you save a vehicle in My Garage, and the calendar reminder is a file created on your device that you choose whether to open.
Does this tell me my tires are safe?
No. It organises measurements you take and compares them with objective references, like the wear bars and your placard pressures. Visible damage, vibration, pulling, or any doubt is a reason to have a tire professional inspect the tire.
Last updated .