Does a high-mileage 2015 to 2018 car fail the MOT more? Pass rates by mileage band

The short answer

Yes, within the same age group, the more miles a car first used 2015 to 2018 had covered, the more often it failed. Tested at six to nine years old, about 1 in 8 cars under 30,000 miles failed or needed a fix on the day (12.8% of 5,078,555 tests). At 150,000 miles and over the figure was about 3 in 10 (29.7% of 719,820 tests). The pass rate fell band by band up to 90,000 miles and then flattened: the three highest bands all sit around 70%.

So mileage shows, but it does not keep getting worse without limit, and the data cannot say the miles themselves are the reason. A car with 120,000 miles at seven years old has usually been a work car, serviced on schedule and driven on motorways. The checks below are how you tell that car from one that has simply been used hard.

What the data shows

The table is the first-test pass rate for cars first used in 2015, 2016, 2017 or 2018, in tests carried out 2021 to 2025, split by the mileage on the clock and by the car's age on the day. Read down a column, never across a row: mileage and age rise together, so comparing a 3-5 cell with a 10-14 cell mixes two things.

The same shape appears in every column. The biggest single step is always from under 30,000 to the 30,000-59,999 band, and the next biggest is the step to 60,000-89,999. Above 90,000 the line is nearly flat; in the 6-9 column the 150,000-and-over cars (70.3%) actually passed slightly more often than the 120,000-149,999 cars (69.7%).

Two cells rest on smaller bases and should be read loosely: cars aged 3-5 with 150,000 miles or more (69,854 tests) and cars aged 10-14 under 30,000 miles (152,602 tests). For this cohort the 10-14 column is only 2015 cars tested in 2025, so it is thin throughout. For context, the national pass rate across all ages and all cars was 72.3% in 2025 and 70.5% in 2021.

Why the line flattens

The data does not say why, but the shape is telling. Cars that reach 120,000 miles by eight years old are rarely neglected cars; they are the ones that were driven for work, serviced because a fleet policy said so, and spent their miles on motorways where brakes, suspension and tyres wear slowly. Cars under 30,000 miles at the same age are mostly private, gently used and still on many of their original parts.

The middle bands are where the mix is widest: some well-kept, some not. That is why the pass rate falls fastest there. By the top bands the population has sorted itself, and what remains is mostly cars that were looked after because they had to be.

What to check on a high-mileage car of this age

1. The history, test by test. The GOV.UK MOT history service lists the mileage at every test since 2005. A steady climb of similar size each year is a work car; a sudden jump or a year that goes backwards is a question for the seller.
2. Service evidence to match the miles. A car at 120,000 miles should have a stack of invoices or a stamped book with dates that line up with the MOT mileages. No records with that mileage is the combination to walk away from.
3. The wear items the data flags. Pads, discs and tyres on a car with big motorway miles are often fine; what gives is suspension bushes, drop links and springs. Push down on each corner and listen for knocks on a test drive over a rough road.
4. Advisories that repeat. An advisory for the same item at two or three tests running means nobody fixed it. On a high-mileage car that is the cheapest clue you will get.
5. Compare like with like. Use the column for the car's age, not the whole table. A 2017 car tested at eight years old sits in the 6-9 column.

What this does not mean

These are pass rates for groups of millions of cars, not predictions for one. A 150,000-mile car with a full history can be a better buy than a car with a fraction of the miles that sat on a drive and was never serviced. Mileage is one of several things that move together with wear and upkeep, and the test records what the tester found, not why. Use the table to set your expectations and your price, then let the history and an inspection decide.

Sources and method

Pass rates are first-test passes divided by first tests, cars first used 2015 to 2018, test years 2021 to 2025 pooled, split by the odometer reading recorded at the test and by vehicle age (test year minus first-used year). Tests with no reading, or a reading under 100 or over 400,000, are excluded (37,759 tests). Cells with fewer than 500 tests are blanked. Bases for the cells quoted in the text: aged 6-9 under 30,000 miles 5,078,555 tests; aged 6-9 150,000 and over 719,820; aged 3-5 150,000 and over 69,854; aged 10-14 under 30,000 152,602. Mileage and age rise together, so the comparison is always within one age band; the data records what was found at the test, not why.

• DVSA anonymised MOT results, class 4 first tests, 2021-2025
• GOV.UK: Check the MOT history of a vehicle

This article is general information drawn from published test records. It is not professional, mechanical or legal advice, and an MOT pass or a clean MOT history does not guarantee that a car is roadworthy today. If you are unsure about a car, have it inspected by a qualified mechanic. You can check any vehicle's MOT history free on the official GOV.UK MOT history service.