Understanding a vehicle’s reliability is essential for any driver, especially when buying a used car. While manufacturers’ ratings and owner reviews help, one of the most valuable and often overlooked tools is MOT data. Every year, millions of vehicles in the UK undergo MOT testing, and the results provide a detailed snapshot of performance, safety, wear, and maintenance habits. So, can MOT data predict vehicle reliability? Here’s what the numbers reveal.

How MOT Data Reflects Real-World Reliability

MOT tests check key components such as brakes, suspension, tyres, emissions, and lights. These are all systems that directly affect everyday performance. When the same issues appear repeatedly across a model or age group, it highlights reliability trends that real drivers experience—not just results from lab testing.

For example, if a specific model consistently records failures for suspension or brake wear earlier than expected, it may indicate design weaknesses or higher maintenance needs. Conversely, a model with fewer failures over time suggests better durability and build quality.

Why Failure Rates Matter

MOT failure rates offer a clear indicator of how well a vehicle ages. Some brands show strong reliability at high mileage, still passing MOT tests with minimal advisories. Others show rising failure rates as early as year five or six.

Patterns to pay attention to include:

• High first-time MOT failure rates, which may indicate initial build issues.
• Increasing failures with age, showing long-term weaknesses.
• Common failure categories, such as suspension or emissions, highlighting costly future repairs.

You can view a vehicle’s full history by using services like CheckMot.com, which reveal pass rates, advisories, odometer records, and more.

Advisory Notes: The Early Warning System

Advisories are often more useful than outright failures. They show parts that are worn or nearing the end of their life. If a car receives the same advisory year after year—such as brake wear, tyre cracking, or corrosion—it may point to poor maintenance or underlying reliability concerns.

Multiple advisories related to the same system can be a red flag when assessing a used vehicle.

MOT Mileage Trends and Reliability

Mileage consistency is another valuable indicator. MOT data shows annual mileage, helping predict how heavily the car has been used. Low-mileage cars with frequent failures may have underlying mechanical issues. High-mileage cars with strong MOT histories are often better maintained and more reliable than expected.

Using MOT Data Before Buying a Used Car

Checking MOT history allows buyers to:

• Identify long-term maintenance habits
• Spot recurring mechanical issues
• Avoid clocked or poorly maintained vehicles
• Estimate potential repair costs
• Compare models for better reliability decisions

In many cases, MOT data can be more telling than a seller’s description or a quick inspection.

FAQs

1. Can MOT data reliably indicate future breakdowns?

Not perfectly, but patterns in failures and advisories can highlight weaknesses and predict future issues.

2. Does a clean MOT history mean the car is highly reliable?

It’s a good sign, but buyers should also consider service records and mileage.

3. Are high MOT failure rates always a bad sign?

Not always—some vehicles fail due to minor issues like bulbs or tyres but are mechanically sound.

4. Should I avoid a car with repeated advisories?

Repeated advisories for the same system can indicate poor maintenance or underlying faults.