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SEAT Mii years to avoid? MOT pass rate by year

18,357 initial MOT tests in 2025 on cars first used 2012–2021 · DVSA data · For guidance only · How we count

No SEAT Mii year has an MOT pass rate clearly below the average for vehicles first used in the same year. Above it: 2012–2015. The other 5 years can't be told apart from average.

The MOT pass rate is one signal, not the whole story. An MOT checks safety and emissions on the day of the test. It doesn't record gearbox or engine faults, and a pass rate also reflects mileage and upkeep, so the table shows median mileage too. Whatever the year, the car in front of you matters more than its model's average.

75.7%passed first time

First-time pass rate, all years together: initial tests passed with no repairs. 95% range 75.1% to 76.4%.

In 2025, 75.7% of the 18,357 initial MOT tests on SEAT Mii cars were passed with no repairs. The same-age average, for all vehicles first used in the same years, was 72.6%. That is 3.1 points above the same-age average.

Check a specific Mii

Its own MOT history, free.

SEAT Mii MOT pass rate by year

Year is when the car was first used. Older vehicles fail more often, so each year is compared with all vehicles first used that year.

YearChartTestsmedian milesPassed first timeAgainst all vehicles that year
2021age 41,08523,00087.3%±2.2+0.1 ptsall: 87.2%
2019age 61,30429,50084.0%±2.1+0.5 ptsall: 83.5%
2018age 71,27735,30082.6%±2.2+1.7 ptsall: 80.9%
2017age 81,47142,20080.1%±2.2+1.9 ptsall: 78.2%
2016age 92,23847,30074.1%±1.9−0.8 ptsall: 74.9%
2015age 102,68153,60073.8%±1.7+1.9 ptsall: 71.9%
2014age 113,08159,70075.3%±1.6+6.7 ptsall: 68.6%
2013age 123,49166,90070.4%±1.6+4.6 ptsall: 65.8%
2012age 131,72971,40070.2%±2.2+6.7 ptsall: 63.5%

Tests are initial MOT tests in 2025, not retests. Median miles is the middle odometer reading at the test: half had more, half had less. ± is the 95% margin of error in points (Wilson interval): a difference smaller than that could be chance. Years without a link have fewer than 10,000 tests, so they are listed here but don't have their own page.

When a car's mileage doesn't add up

Does mileage matter?

SEAT Mii first-time pass rates by the mileage at the initial test, all years together, against all vehicles of the same age and mileage.

87.9% of SEAT Mii tests under 30,000 miles passed first time, against 60.7% at 90,000 to 119,999 miles. For all vehicles of the same age and mileage, the figures are 87.5% and 63.6%.

Miles at the testTestsPassed first timeAgainst all vehicles, same age and mileage
Under 30,0003,81787.9%±1.1+0.4 ptsall: 87.5%
30,000–59,9997,49178.3%±1.0+0.7 ptsall: 77.7%
60,000–89,9994,93169.3%±1.4+0.8 ptsall: 68.5%
90,000–119,9991,63860.7%±2.4−2.8 ptsall: 63.6%

Against all vehicles of the same age and mileage, Mii tests were about average under 90,000 miles and below average at 90,000 to 119,999 miles.

Mileage is only one factor. How a car has been driven and looked after matters too. These figures show an association across all SEAT Mii tests in 2025, not what mileage does to a particular car.

Mileage is the odometer reading at the initial test. Each band is compared with all vehicles first used in the same year with a reading in the same band, weighted by this model's own tests in each year. Bands need at least 1,000 tests. Not shown, with fewer than 1,000 tests: 120,000 or more. 11 tests (0.1%) had no usable odometer reading and are left out. How we count

Common Mii problems at the MOT

Share of the 4,453 failed tests with a fault in each area, all years together. A test can count in more than one area, so these add up to more than 100%.

MOT records show roadworthiness faults, not engine or gearbox problems. Each year page compares that year's failure areas with all vehicles first used in the same year.

What to check when viewing a Mii

Based on the areas where SEAT Mii MOT tests fail most often. These are general checks anyone can do, not a mechanical inspection.

  1. Lights and electrics

    In 36.2% of failed Mii tests

    • Ask the seller to help you check every light: dipped and main beam, brake lights, indicators, fog lights and the number plate lamp.
    • Look for cracked, misted or yellowed headlight lenses.
    • Warning lights on the dashboard should come on with the ignition and go out once the engine starts.

  2. Brakes

    In 23.0% of failed Mii tests

    • On a clear road, brake firmly. The car should stop in a straight line without juddering or pulling to one side.
    • Check the handbrake holds the car on a slope.
    • Look through the wheels at the brake discs for deep grooves or a raised lip at the edge.

  3. Tyres

    In 16.8% of failed Mii tests

    • Check the tread on every tyre. The legal minimum for cars is 1.6 mm across the central three-quarters of the tread.
    • Look for cuts, bulges, and wear on only the inner or outer edge, which can point to an alignment problem.
    • Check that the spare wheel or the tyre repair kit is there.

Then read the car's own MOT history. Advisories in the same area at several tests are worth asking about.

Check a Mii's MOT history

After an MOT advisory

SEAT Mii cars that passed their 2024 MOT first time with an advisory, and what their next MOT found, against similar cars that passed with nothing noted in that area. All first-use years together.

Tyres

Of SEAT Mii cars that passed their 2024 MOT with a tyre advisory and came back for their next MOT 10–14 months later, 6.7% failed on tyres, against 3.1% of similar cars with nothing noted. Based on 2,444 and 8,936 cars.

  • With a tyre advisory6.7%
  • Similar cars, nothing noted3.1%

Cars not tested again in that window are not included: 7.4% of those with a tyre advisory and 7.3% of the others.

Brakes

Of SEAT Mii cars that passed their 2024 MOT with a brake advisory and came back for their next MOT 10–14 months later, 10.5% failed on brakes, against 4.3% of similar cars with nothing noted. Based on 1,577 and 9,851 cars.

  • With a brake advisory10.5%
  • Similar cars, nothing noted4.3%

Cars not tested again in that window are not included: 7.6% of those with a brake advisory and 7.2% of the others.

Similar cars are the same model, first-use year and mileage band. Areas are the DVSA's top-level groups, so the later fail may not be the fault that was advised. These figures describe what happened to these cars. They don't show what a repair would have changed.

How we worked this outAll models compared, with the data

SEAT Mii questions

Which SEAT Mii years have lower MOT pass rates?

Compared with all vehicles first used in the same year, no model year is clearly below average. Above average: 2012–2015. The rest can't be told apart from average. A pass rate is one signal: it also reflects mileage and upkeep, and doesn't record engine or gearbox faults.

Is the SEAT Mii reliable?

MOT results show only part of the picture. In 2025, 75.7% of initial MOT tests on SEAT Mii cars were passed with no repairs, against a same-age average of 72.6%. That is 3.1 points above average. An MOT checks safety and emissions on the day of the test. It doesn't measure breakdowns, engine or gearbox faults, or repair costs.

What are the most common SEAT Mii problems at the MOT?

The most common failure areas are lights and electrics (in 36.2% of failed tests), brakes (in 23.0% of failed tests) and tyres (in 16.8% of failed tests). A failed test can count in more than one area.

What mileage is normal for a 10-year-old SEAT Mii?

At their 2025 MOT tests, SEAT Mii cars first used in 2015, about 10 years old, had a median of 53,600 miles. Half had more and half had less.

How do I check a specific Mii's MOT history?

Enter its registration in our free check. It lists that car's own MOT results, the faults and advisories recorded and the mileage at each test, and flags repeated advisories and mileage that goes down.

Check a car's MOT history for free

What MOT data can't tell you about any SEAT Mii

Outstanding finance, write-offs, theft and plate changes aren't in MOT records. For a particular car, you need a history check.

Compare history checksWhat MOT history doesn't show

Other SEAT models

Points above (+) or below (−) the same-age average for all vehicles.

All 8 SEAT modelsCars ranked by MOT pass rate, by age

Source: DVSA anonymised MOT tests, 2025. For guidance only: these figures describe all SEAT Mii cars tested, not the one you're looking at. How we count