Tyre Failures: Avoid Your MOT Nightmare

It’s that time of year again – the dreaded MOT test. While many motorists are familiar with common reasons for failing, such as faulty lights or worn brakes, the significant role tyres play in a successful MOT might come as a surprise. At AJS Tyres, we’ve seen it all, and the statistics are quite telling: a staggering 14% of MOT failures are attributed to issues with tyres. This is a stark reminder that your tyres are not just about getting from A to B; they are a critical component of your vehicle's safety and are rigorously inspected during your annual MOT. Fortunately, with a little knowledge and proactive care, you can significantly reduce the risk of your tyres letting you down.

Tyre Tread: The Foundation of Safety

The legal minimum tyre tread depth in the UK is a mere 1.6mm. However, as tyre experts, and in line with recommendations from manufacturers like General Tire and the DVLA, we strongly advise maintaining at least 3mm of tread. Why this extra margin? Deeper tread provides crucial grip on the road surface, directly impacting your ability to brake effectively, steer accurately, and accelerate with confidence. Insufficient tread is a primary reason for MOT failure, and it significantly compromises your safety, especially in wet conditions.

Checking Your Tread Depth: The 20p Test

You don’t need special equipment to check your tread depth. A simple yet effective method is the 20p coin test. Insert a 20p coin into the deepest groove of your tyre. If you can see any part of the outer rim of the coin, your tread depth is below the legal minimum of 1.6mm, and your vehicle will fail its MOT. It’s important to check this across the entire width of the tyre, as wear can be uneven.

Understanding Uneven Tyre Wear

Uneven tyre wear is another pitfall that can lead to an MOT failure, even if other parts of the tyre have sufficient tread. This often stems from incorrect tyre pressures or issues with your vehicle’s wheel alignment or suspension. Maintaining the correct tyre pressures is paramount not only for safety but also for fuel efficiency and extending the life of your tyres. Smooth, shiny patches on the tyre surface are tell-tale signs of excessive wear and should be addressed immediately.

Sidewall Damage: A Critical Safety Concern

The sidewalls of your tyres are the unsung heroes, absorbing the constant pressures and impacts of driving. Any damage here – be it cuts, nicks, bulges, or bubbles – is a serious safety hazard and a guaranteed MOT fail. Such damage can lead to a sudden tyre blowout, drastically increasing the risk of a severe accident. It’s vital to be vigilant about the condition of your tyre sidewalls.

Five Tips to Prevent Sidewall Damage:

1. Avoid Kerbing: Regularly scuffing your tyres against kerbs, especially during parking manoeuvres, can cause significant sidewall damage. Be mindful of your steering and positioning when parking near kerbs.
2. Beware of Potholes: While often unavoidable, hitting potholes with force can severely compromise the integrity of your tyres and suspension. While difficult to completely avoid, drive cautiously and try to steer around them when safe to do so.
3. Maintain Correct Tyre Pressures: As mentioned, correct inflation is key. Under-inflated tyres place excessive stress on the sidewalls, making them more susceptible to damage. Over-inflated tyres can also lead to premature wear and reduced grip.
4. Keep Tyres Clean: Prolonged exposure to contaminants like oil, solvents, or harsh chemicals can soften the rubber compound of your tyres, making the sidewalls more vulnerable. A simple rinse with water can help remove harmful residues.
5. Inspect for Sharp Objects: Nails, glass, and other sharp debris can become embedded in both the tread and sidewalls of your tyres. Regularly inspect your tyres for any such objects. If you find one, it’s often best to have it professionally removed and the tyre inspected, as leaving it can lead to further damage or a puncture. Prompt removal of embedded objects can prevent more serious issues.

Regular visual inspections of your tyres are invaluable. They not only enhance your safety on the road but also serve as a proactive measure against failing your MOT due to tyre defects.

Tyre Pressure Monitoring Systems (TPMS): Modern Tech, Modern Failures

With the increasing prevalence of Tyre Pressure Monitoring Systems (TPMS) in modern vehicles, another potential MOT failure point has emerged. If your TPMS malfunctions, your vehicle will fail its MOT. Common causes include faulty or depleted internal batteries, but it’s also crucial to remember that TPMS often needs to be reset after tyres are replaced or pressure is adjusted. A discrepancy between the TPMS readings and a manual pressure check during the MOT will result in a fail.

TPMS and MOT: What You Need to Know

• Functionality: TPMS alerts drivers to under or over-inflated tyres.
• Common Failures: Battery issues, sensor malfunctions, or incorrect system settings.
• Post-Tyre Change: Ensure your TPMS is correctly reset after new tyres are fitted or pressures are adjusted.
• Discrepancies: Mismatched pressure readings between TPMS and manual checks will lead to a fail.

Ensuring Your Tyres Pass the MOT

Proactive tyre maintenance is the key to a smooth MOT experience. Regularly checking your tread depth, inspecting for any signs of damage on the sidewalls, and ensuring your tyre pressures are correct will go a long way. Don't forget the importance of a functioning TPMS if your vehicle is equipped with one.

Frequently Asked Questions About Tyres and MOTs:

Q1: What is the minimum legal tyre tread depth in the UK?
A1: The legal minimum is 1.6mm across the central three-quarters of the breadth of the tread.

Q2: Can I use a 1p coin to check my tread depth?
A2: While a 1p coin can give you a rough idea, the 20p coin test is recommended as it more accurately indicates if you are below the 1.6mm legal limit.

Q3: What kind of sidewall damage will cause my car to fail its MOT?
A3: Any cut, snag, abrasion, or other damage that is more than 10% of the tyre’s width or depth, or that exposes the ply or cord structure, will result in a fail.

Q4: How often should I check my tyre pressures?
A4: It’s recommended to check your tyre pressures at least once a month and before any long journeys.

Q5: What happens if my TPMS light is on during the MOT?
A5: If the TPMS warning light indicates a system fault (not just a low-pressure warning), your vehicle will fail the MOT.

Expert Advice from AJS Tyres

Navigating the complexities of MOT requirements for your tyres can seem daunting, but it doesn’t have to be. If you have any doubts about whether your tyres are roadworthy or MOT-ready, don’t hesitate to visit AJS Tyres in Reigate. Our team, with over 30 years of combined experience, offers expert advice and comprehensive tyre services. We can help you identify any potential issues and provide solutions, including great deals on General Tire products and professional fitting. Ensure your vehicle is safe and compliant by booking an appointment with us today. You can reach us by telephone on 01737 241370 or book your service online. Let us help you avoid the disappointment and inconvenience of an MOT tyre fail.