How to Inspect Tyre Tread Before It Costs You

A tyre can look fine when you glance at it on the driveway, then fail an MOT or lose grip badly in heavy rain. Knowing how to inspect tyre tread takes only a few minutes, but it can spot a safety issue before it turns into a puncture, poor braking or an unexpected bill.

At AutoFix4u, we often see tyres brought in because a driver has noticed one bald edge, a steering pull or an MOT advisory. In most cases, the tyre wear has been developing for months. A quick regular check gives you time to deal with the cause properly, whether that is simply a replacement tyre, incorrect pressures or a wheel alignment problem.

Start with a proper look at all four tyres

Park on level ground, apply the handbrake and turn the steering wheel fully to one side so you can see the front tyre faces. Check the rear tyres too. Do not rely on looking at just the outer edge, as the worst wear is often hidden on the inside shoulder.

Look across the full width of each tread and around as much of the tyre circumference as you can see. Roll the car forward a short distance if needed, with the engine off and the vehicle secure, to inspect the section that was touching the ground.

You are looking for more than low tread. Watch for cuts, cracks, bulges, stones or screws, and areas where the tread has worn differently from the rest of the tyre. A bulge in the sidewall is particularly serious. It can mean internal tyre damage, often after hitting a pothole or kerb. Do not continue driving on it other than to get immediate professional advice.

How to inspect tyre tread depth

The legal minimum tread depth for cars in the UK is 1.6mm across the central three-quarters of the tyre, around its full circumference. If any section is below that limit, the tyre is illegal and unsafe to use. It can also lead to an MOT failure and penalty points if you are stopped.

A tread-depth gauge is the clearest way to check. They are inexpensive and give you a reading in millimetres. Measure in several grooves across each tyre, rather than one place only. A tyre can have plenty of tread in the middle but be worn close to the limit on one edge.

If you do not have a gauge, use the tyre’s built-in wear indicators. These are small raised bars set across the main grooves. When the tread surface is level with those bars, the tyre has reached the legal limit and needs replacing.

The 20p coin check is also useful as a quick guide. Put a 20p coin into the main tread groove. If the outer border of the coin is covered, there should be more than 1.6mm of tread. Repeat this in several places across the tyre. It is not as accurate as a gauge, but it can highlight a tyre that needs checking properly.

Do not wait until a tyre is exactly at the legal limit. Wet-weather grip drops well before 1.6mm because the tread has less depth to move water away from the road. For a car used for commuting, school runs or regular longer journeys, planning a replacement earlier is usually the sensible option.

Check the spare if your car has one

A spare tyre is easy to forget until it is needed at the roadside. Check its tread, sidewall condition and pressure at the same time. If it is a space-saver, make sure you know its speed restriction and that it is suitable only for temporary use.

Uneven tyre wear tells you something is wrong

Uneven wear is where a basic tyre check becomes a useful early warning. The pattern often points to the underlying fault.

If both outer edges are worn, the tyres may have been run too soft. Under-inflation makes the shoulders of the tyre carry more of the load. If the centre is worn more than the edges, over-inflation is a common cause.

Wear mainly on one inner or outer edge usually suggests wheel alignment is out. This can happen after pothole damage, clipping a kerb or worn suspension components. The car may pull to one side, the steering wheel may sit off-centre, or you may notice the tyres becoming noisy. Replacing the tyre without checking the alignment can mean the new one wears out in the same way.

Patchy, scalloped or cupped wear can point to worn shock absorbers, suspension bushes or an imbalance issue. We often see this when drivers report a humming noise that gets louder with road speed, even though the engine sounds normal.

A tyre with different wear patterns on the same surface needs attention, not guesswork. A garage can inspect the tyre, check pressures, look over the suspension and measure alignment before recommending the right repair plan.

Do not ignore cracks, damage or objects in the tread

Tread depth is only part of the picture. Check for nails, screws, flints and deep cuts. A screw may not cause an instant flat because it can partly seal the hole, but pulling it out at home can turn a slow leak into a flat tyre. Leave it in place and arrange a tyre inspection.

Small surface cracks can appear as tyres age, especially if the car is parked outside for long periods or used infrequently. Deep cracks, exposed cords, splits or sidewall damage are not repairable. The tyre will need replacing.

If the tyre is losing pressure repeatedly, do not keep topping it up and hoping for the best. It could be a puncture, a damaged valve, corrosion around the wheel rim or a fault with the tyre pressure monitoring system. Finding the source is safer and usually saves time in the long run.

When should you inspect your tyres?

A monthly check is a sensible routine, and it is worth doing before a long journey, an MOT or a spell of colder, wetter weather. Check after a hard pothole strike or kerb impact too, even if the car still feels normal.

It is also time to inspect the tyres if you notice any change in how the car drives. Common signs include vibration through the steering wheel, a pull to one side, a new road-noise hum, the tyre-pressure warning light or reduced confidence in the wet. These symptoms do not always mean the tyre itself is the only issue, but they need checking.

Tyre pressures should be checked cold, using the vehicle manufacturer’s recommended settings. The correct figures are usually on a sticker inside the driver’s door frame, fuel flap or in the handbook. Pressure affects tyre wear, braking, handling and fuel use, so it goes hand in hand with tread checks.

What to do when the tread is low or uneven

If the tread is near the legal limit, visibly uneven or damaged, arrange a tyre check promptly. Do not put off an inspection because the car is still moving normally. Tyres can deteriorate gradually, and the first obvious warning may be an MOT failure or poor grip when you need it most.

A straightforward tyre replacement may be all that is needed. But if one tyre has worn much faster than the others, ask for the cause to be checked as well. Correcting pressure, alignment or a suspension fault protects the replacement tyre and helps the car drive as it should.

For drivers in Lowestoft and the surrounding area, AutoFix4u can inspect tyre condition, identify uneven wear and explain the next step in plain English. You will get clear advice on whether the tyre needs replacing now and whether there is another fault behind the wear. Call for a tyre check or get a quote – catching the issue early is always easier than dealing with it at the roadside.