Car Tyres and MOT Explained: What Every Driver Needs to Know

Why do many cars fail their MOT test because of simple tyre problems which take only a few minutes to spot on a driveway? The tyres are the point of contact between a vehicle and the road surface. People looking for car tyres in Swindon find simple home maintenance not only prevents surprise failures during the test but also helps reduce running costs.

A test is carried out every year and involves the examination of a large number of mechanical parts. If drivers take ten minutes to examine their tyres at home, they will have enough time to sort out any problems before going to the testing bay. A rapid visual inspection helps drivers spot irregular wear patterns early, preventing expensive tyres from suffering permanent damage.

Measuring Tread Depth Across the Central Band

Under UK law, the minimum allowable tread depth is 1.6 millimetres. This rule applies to the central three-quarters of the tyre. Tread depth is the vertical distance measured from the top of the rubber to the bottom of the main grooves. These grooves clear water from the road surface and help prevent aquaplaning, where a tyre rides on water rather than holding onto the tarmac.

A driver can use a specialised tread gauge or look at the built-in tread wear indicators to check the depth. These small rubber bars are positioned within the main grooves and are at the same level as the tread surface when the rubber has worn down to the legally permitted limit. By examining a number of different areas of the tyre, it is possible to determine whether the rubber remains fit for use over the entire tread.

Checking the Sidewall for Structural Damage

How can a driver detect dangerous structural damage on the tyre sidewall without using workshop tools? The sidewall refers to the rubber portion lying between the wheel rim and the tread face. Drivers should look for bulges, deep cuts, or any visible internal cords which indicate that the internal casing structure is weakened. 

Any tyre that has a bulge in the sidewall is structurally unsafe and will fail the MOT test in Swindon. If damage is noticed, motorists can fit a new tyre before a blowout occurs on faster roads.

Monitoring Cold Tyre Pressures at Home

The right air pressure makes sure that the whole of the contact patch touches the road evenly. When the tyres are underinflated, excessive weight is placed on the sides. If the tyres are overinflated, pressure is applied to the central strip, which causes rapid, uneven wear.

When measuring tyre pressures drivers must check when the tyres are cold. The correct pressure to aim for is given in the vehicle handbook or on the tyre placard located inside the driver's door pillar, in units of pounds per square inch or bar. Setting the precise pressure values helps to maintain braking stability and prevents uneven tyre wear which MOT inspectors note on their inspection sheets.

Identifying Irregular Wear and Tracking Issues