How to Check Tyre Tread: A Simple Safety Check

A tyre can look perfectly serviceable from a few steps away, yet have too little grip for a wet Essex road. Knowing how to check tyre tread takes only a few minutes and can help you spot a problem before it affects braking, steering or your next MOT.

For most cars, vans and motorhomes, the legal minimum tread depth is 1.6mm across the central three-quarters of the tyre’s width, around its entire circumference. That is the legal limit, not the point at which a tyre is performing at its best. Many drivers choose to replace tyres nearer 3mm, particularly before winter or if they regularly cover motorway miles.

How to Check Tyre Tread at Home

Park on level ground, apply the handbrake and turn the steering wheel so you can see the front tyre tread more clearly. Check all four tyres, rather than assuming they will wear at the same rate. The rear tyres can wear differently to the fronts, especially on vehicles that carry passengers, tools or heavy loads.

Look at several points around each tyre. You may need to roll the vehicle forward a short distance to inspect the section that was touching the ground. Do not rely on one quick look at the outer edge, as the lowest point of the tread could be elsewhere.

Use the built-in tread wear indicators

Most modern tyres have tread wear indicators moulded into their main grooves. These are small raised bars running across the groove. You can usually find their location from small triangle, TWI or brand markings on the tyre sidewall.

When the surrounding tread is level with these bars, the tyre is at approximately 1.6mm and needs replacing. This is a useful visual warning, but it is still worth checking the tyre in more than one place. A tyre can be legal in one area and worn below the limit elsewhere.

Check with a tread-depth gauge

A tyre tread-depth gauge is the clearest way to measure what is left. Place the gauge’s probe into a main groove, making sure it reaches the base of the groove rather than sitting on a raised section. Take readings from the inner, centre and outer portions of the tyre, then repeat around its circumference.

For cars, vans and motorhomes, you are looking for at least 1.6mm in the central three-quarters of the tread, all the way round. If a reading is close to the limit, do not leave it until the next service. Tread can disappear more quickly than expected with frequent driving, heavy loads or poor wheel alignment.

A 20p coin is a handy rough check when a gauge is not available. Put the coin into a main tread groove. If the outer band of the coin is obscured, there is generally more than 1.6mm remaining. If you can see the outer band, arrange a proper measurement and expect that the tyre may need replacement. The coin test is convenient, but it cannot identify uneven wear or provide a precise reading.

Check the Whole Tyre, Not Just the Tread

Tread depth matters, but it is not the only point checked during an MOT or a proper tyre inspection. Take a moment to look over the sidewalls and tread surface for cuts, cracks, bulges, exposed cords, embedded objects and signs of a slow puncture.

A bulge in the sidewall can indicate internal damage, often after a pothole strike or kerb impact. It is not something to monitor and hope for the best. Avoid driving on it where possible and have the tyre assessed promptly. Likewise, a nail or screw may not cause an immediate flat tyre, but removing it yourself can turn a slow leak into a rapid loss of pressure.

Also check tyre pressures when the tyres are cold, using the vehicle manufacturer’s recommended figures. These are normally shown inside the driver’s door frame, behind the fuel flap or in the handbook. The pressure marked on the tyre itself is a maximum rating, not usually the pressure your vehicle should run.

What Uneven Tyre Wear Can Tell You

A tyre wearing evenly across its width is usually a good sign. Wear concentrated on one edge, through the centre, or in patchy areas can point to an issue that fitting a new tyre alone will not solve.

Wear on both outer shoulders often suggests under-inflation. The tyre flexes more than it should, creating heat and placing extra load on the edges. Centre wear can suggest over-inflation, although the correct pressure should always be confirmed against the vehicle information rather than guessed.

One-sided wear may be caused by wheel alignment being out, commonly after hitting a pothole or kerb. Cupping, scalloped patches or irregular wear can be linked to worn suspension components, wheel balance concerns or a damaged wheel. On older and classic vehicles, where suspension bushes and steering parts may have seen many years of use, a careful inspection can be particularly worthwhile.

If a new tyre is fitted without addressing the underlying cause, the replacement may wear prematurely too. A garage inspection can establish whether the issue is tyre pressure, alignment, suspension or another mechanical fault, helping you avoid paying twice for the same problem.

Legal Tread Depth for Motorcycles

Motorcycle tyres follow different rules. For motorcycles over 50cc, the minimum tread depth is 1mm across at least three-quarters of the tread pattern, around the full circumference. For smaller motorcycles and mopeds, the tyre must have a visible tread pattern.

The legal difference does not mean riders should wait for 1mm. Motorcycle tyres have a direct effect on grip, stability and confidence through bends, especially in rain. Check for squared-off rear tyres, cracking, punctures and uneven wear, and do not overlook tyre age. A tyre with reasonable tread but hardened rubber or visible cracking deserves professional advice.

When to Replace a Tyre

Replace a tyre if it is below the legal tread limit, has damage that cannot be safely repaired, or is wearing unevenly to the point that its road contact is compromised. You should also consider replacement before the legal limit if you are heading into colder, wetter months, travelling long distances or carrying a full family, holiday luggage or work equipment.

There is a practical trade-off here. Getting every last millimetre from a tyre may seem economical, but wet-weather performance reduces as the grooves become shallower and have less water to clear. Replacing tyres earlier can offer better grip and a greater safety margin, particularly on busy A-roads and standing-water-prone routes around the local area.

If only one tyre needs replacing, the correct choice depends on the vehicle, the remaining tread on the matching tyre and the tyre manufacturer’s guidance. Four-wheel-drive vehicles can be especially sensitive to significant differences in tyre circumference. A trained technician can advise on the safest and most suitable option rather than applying a one-size-fits-all answer.

How Often Should You Inspect Your Tyres?

A monthly check is a sensible routine, along with a look before a long journey, an MOT, or a change in season. Check again after a heavy pothole impact, a kerb strike or a warning from the tyre-pressure monitoring system.

It is also wise to inspect tyres before loading up a van or motorhome. Extra weight increases the demand placed on tyres, and the correct pressure may differ from normal day-to-day driving. Consult the vehicle handbook for loaded pressures rather than simply adding air by guesswork.

A quick tread check is one of the simplest habits a driver can build. If the readings are close, the wear looks uneven or something about a tyre does not look right, let a qualified mechanic examine it. At Halfway Garage, we treat tyre and vehicle safety checks with the same care we would want for our own journeys - clear advice, practical work and no unnecessary fuss.