21/06/2018
When the time comes for your annual MOT test, many drivers naturally wonder about every component of their vehicle, including the often-overlooked spare tyre. It's a common question: does that tyre, tucked away in your boot or mounted beneath your vehicle, undergo the same rigorous scrutiny as the four tyres actively supporting your car?
The straightforward answer is that, generally, the spare tyre itself is not a specific testable item during a standard MOT inspection. The MOT test, designed to ensure your vehicle meets minimum road safety and environmental standards, primarily focuses on components that are actively fitted and in use on the vehicle at the time of the test. This means the four wheels and tyres that are on your vehicle are the ones that will be thoroughly checked.
The MOT: A Safety & Roadworthiness Assessment
Before delving deeper into tyre specifics, it's crucial to understand the fundamental purpose of the MOT. The Ministry of Transport (MOT) test is an annual inspection of vehicle safety, roadworthiness, and exhaust emissions required for most vehicles over three years old in the UK. Unlike a service, which is designed to maintain your car's mechanical health and efficiency, the MOT is purely a legal compliance check. It's a visual inspection, and while faults are identified, no repairs are carried out by the tester.
Driving without a valid MOT certificate is illegal and can result in significant fines, invalidate your insurance, and prevent you from renewing your vehicle tax. It's an essential part of responsible vehicle ownership, ensuring that your car is safe for you, your passengers, and other road users.
What the MOT *Does* Check on Tyres
While your spare tyre might get a reprieve, the four tyres fitted to your vehicle are under intense scrutiny. These are critical components directly impacting your car's handling, braking, and overall safety. The MOT examiner will pay close attention to several key aspects:
- Tread Depth: This is perhaps the most well-known check. The legal minimum tread depth for cars in the UK is 1.6mm across the central three-quarters of the tread around the entire circumference of the tyre. Anything less will result in an MOT failure.
- Tyre Condition: Examiners look for any signs of damage, such as cuts, bulges, lumps, or tears in the tyre wall or tread that could compromise its integrity. Exposed cords are an immediate failure.
- Tyre Pressure: While not a direct pass/fail item, severely under-inflated tyres can indicate a potential issue and may be advised upon. However, the primary focus is on the structural integrity and tread.
- Correct Size and Type: All tyres on the same axle must be of the same type (e.g., radial or cross-ply) and generally the same size. There are specific rules regarding mixing tyre types, which can lead to a fail.
- Valve Condition: Tyre valves must be secure and free from damage.
- Wheel Condition: The wheels themselves are also inspected for cracks, distortion, or damage that could affect the tyre's seating or the wheel's integrity.
It's worth noting that if your vehicle has a tyre pressure monitoring system (TPMS) warning light illuminated on the dashboard, this *will* result in an MOT failure, as it indicates a fault with a safety system.
Why the Spare Tyre Isn't Checked (Usually)
The reason the spare tyre isn't typically part of the MOT test is that it's not considered a 'fitted' component essential for the vehicle's immediate roadworthiness. It's a contingency item, there for emergencies. The MOT is about the vehicle as it is presented for use on the road. If a vehicle has a spare tyre permanently fitted and in use (e.g., some older 4x4s with an external spare acting as a fifth wheel in a dual-wheel setup, though rare), then that tyre *would* be subject to inspection. However, for the vast majority of passenger cars with a spare in the boot or under the chassis, it's exempt.
Table: MOT Tyre Checks vs. Recommended Tyre Maintenance
| Aspect | MOT Tyre Check (Fitted Tyres) | Recommended Tyre Maintenance (All Tyres, including Spare) |
|---|---|---|
| Tread Depth | Minimum 1.6mm across central 3/4 circumference | Regularly check for adequate depth, replace well before legal minimum for optimal performance |
| Condition (Cuts, Bulges) | Inspected for damage compromising integrity | Visually inspect regularly for any signs of wear, damage, or foreign objects |
| Pressure | Not a direct pass/fail, but severe under-inflation may be advised | Check monthly (including spare) and before long journeys, adjust to manufacturer's specifications |
| Valve Condition | Must be secure and free from damage | Check for cracks or leaks, ensure valve caps are present |
| Wheel Condition | Inspected for damage, cracks, distortion | Inspect for signs of damage, corrosion, or buckling |
| Age | Not a direct MOT check item | Consider replacing tyres over 6-10 years old, regardless of tread, due to rubber degradation |
| Rotation/Balance | Not an MOT check item | Rotate tyres periodically for even wear; balance wheels when new tyres are fitted or after repair |
The Importance of Maintaining Your Spare Tyre
While the MOT might overlook your spare, you shouldn't. Imagine being stranded with a flat tyre, only to discover your spare is also flat, perished, or completely unsuited for use. Regular maintenance of your spare tyre is just as vital as looking after your main set.
- Check Pressure: Spare tyres can lose pressure over time. Check its inflation regularly, ideally at the same time you check your other tyres, and keep it at the manufacturer's recommended pressure.
- Inspect Condition: Even if stored, rubber can degrade. Look for cracks, bulges, or perishing. Ensure it's free from debris or damage.
- Accessibility: Make sure you can actually get to your spare tyre and that the tools needed to change it (jack, wheel brace) are present and in good working order.
- Space-Savers: If you have a 'space-saver' spare, understand its limitations. These are designed for temporary use only, often with speed and distance restrictions.
Many modern cars are now equipped with tyre repair kits instead of physical spare tyres. If your vehicle relies on a repair kit, ensure it's within its expiry date and that you understand how to use it. While the kit itself isn't MOT checked, the *absence* of a spare or repair kit won't fail you, but being prepared for a puncture is always wise.
Preparing for Your MOT: Beyond the Tyres
To give your vehicle the best chance of passing its MOT first time, it's always a good idea to perform some simple pre-checks:
- Lights: Check all lights – headlights (main and dipped beam), sidelights, brake lights, indicators, fog lights, and number plate lights. Ensure they are clean and working correctly.
- Brakes: Listen for any grinding noises and check if the car pulls to one side when braking. If safe to do so, check your handbrake holds the vehicle firmly.
- Windscreen Wipers & Washers: Ensure wipers clear the screen effectively without smearing, and that washers squirt fluid onto the screen. Top up your screenwash if needed.
- Horn: Give it a quick blast to ensure it works and is loud enough.
- Seatbelts: Pull each belt fully out to check for cuts or fraying, and ensure they retract smoothly. Check that the buckles latch securely.
- Fluid Levels: While not direct MOT items, ensuring adequate oil, coolant, and brake fluid levels is good practice.
- Dashboard Warning Lights: If any warning lights are illuminated (e.g., engine management, ABS, airbag), these can cause an automatic MOT failure.
Combining your MOT with an annual service is often a smart move. A service addresses the mechanical health of your vehicle, identifying potential issues before they become serious and helping to ensure your car runs efficiently. This proactive approach can help you avoid unexpected MOT failures and costly repairs down the line.
Frequently Asked Questions About MOTs and Tyres
Q: Can I fail my MOT for having mismatched tyres?
A: Yes, you can. Tyres on the same axle must be of the same type (e.g., radial or cross-ply). While it's generally recommended to have four identical tyres, the MOT specific check is for axle uniformity in terms of construction type. Significant differences in tread pattern or size between tyres on the same axle can also be a reason for failure.
Q: What if my car has run-flat tyres instead of a spare? Are they checked differently?
A: Run-flat tyres are treated like any other fitted tyre during the MOT. The examiner will check their tread depth, condition, and ensure they are free from damage. If your car is equipped with a TPMS (Tyre Pressure Monitoring System) for run-flats and its warning light is on, this will result in a failure.
Q: Is tyre pressure checked during an MOT?
A: No, tyre pressure itself is not a specific pass/fail item for an MOT. However, if a tyre is severely under-inflated to the point where its structural integrity is compromised (e.g., bulging sidewalls), or if it's so low it indicates a puncture, it could be failed for condition. Additionally, if your TPMS light is illuminated, that *is* an MOT failure.
Q: How can I tell if my tyres need replacing before my MOT?
A: The easiest way is to use the built-in tread wear indicators, small bars in the main grooves of the tyre. When the tyre tread wears down to the level of these bars, it means you've reached the legal minimum of 1.6mm and the tyre needs replacing. You can also use a 20p coin: insert it into the main tread grooves; if you can see the outer band of the coin, your tread is likely below 1.6mm.
Q: Will an old, but unused, spare tyre still be safe to use?
A: Tyres have a shelf life, even if unused. Rubber degrades over time due to exposure to oxygen, UV light, and temperature fluctuations. Most tyre manufacturers recommend replacing tyres after 6-10 years, regardless of tread depth. An old spare might look fine but could be brittle and unsafe when put under load.
Conclusion: Safety First, Always
While your spare tyre might not be a direct focus of the MOT, understanding what *is* checked is paramount for vehicle safety and legal compliance. The MOT is a vital annual assessment, ensuring your vehicle's critical components, especially the tyres, are up to scratch. Always prioritise regular maintenance for all your tyres – including the spare – to ensure you're prepared for any eventuality on the road. A well-maintained vehicle not only passes its MOT with ease but, more importantly, keeps you and your loved ones safe on every journey.
If you want to read more articles similar to MOT & Your Spare Tyre: What Gets Checked?, you can visit the Maintenance category.