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SEAT Mii reliability

C · Average

MOT pass rates and common problems from 143,561 MOT tests of cars first registered 2012–2021.

Jump to: YearsEnginesCommon failures
79.1%pass first time
−0.3 ptsvs typical car
Beats 48%of cars
143,561MOT tests

Verdict

The SEAT Mii passes its MOT first time on 79.1% of tests, about the same as a typical car of the same age and mileage (79.4%). That puts it ahead of 48% of cars on UK roads once age and mileage are taken into account.

By year of first registration, the 2014 Mii does best (beats 63% of cars) and the 2015 worst (beats 40%).

Better than average on tyres, suspension.

Watch these weak spots

Seat belts & airbags4.9×as often as a typical car
Body & structure1.4×as often as a typical car
Airbag warning light8.4×as often as a typical car
Brake performance3.1×as often as a typical car

MOT pass rate by age

First-time pass rate at each MOT by the car’s age in years.

60%70%80%90%100%3456789101112131488%82%80%76%73%69%
SEAT MiiTypical car, same age & mileage

Best and worst years

By year of first registration, ranked against all cars on UK roads after adjusting for age and mileage. Green = better than half of cars.

2012
Beats 59%
2013
Beats 55%
2014
Beats 63%
2015
Beats 40%
2016
Beats 19%
2017
Beats 27%
2018
Beats 26%
2019
Beats 42%
2020
Beats 20%
2021
Beats 15%

Engines

All years, most common first. Grades compare each car with cars of the same age and mileage (A = best 20% of cars on UK roads, E = worst 20%), so an older or higher-mileage car can grade above one with a higher pass rate.

EngineYearsTestsPass rateRankGrade
1.0 Petrol2012–2019139,32178.9%Beats 48%C
Electric2020–20214,24087.0%Beats 16%E

Where it fails

Each area compared with a typical car of the same age and mileage, in points of pass rate. Tap or hover an area to see what to check.

Exhaust: 1.5% of tests fail on emissions & leaks, against 1.4% for a typical car of the same age and mileage. Listen for a blowing exhaust at start-up and look underneath for oil or fluid leaks.Suspension: 2.4% of tests fail on suspension, against 4.9% for a typical car of the same age and mileage. Listen for knocks over speed bumps and push each corner down: it should settle at once.Lights: 7.3% of tests fail on lights & electrics, against 6.6% for a typical car of the same age and mileage. Walk round the car with every light on, including brake, fog and number plate lights.Tyres: 3.8% of tests fail on tyres, against 5.1% for a typical car of the same age and mileage. Check the tread on every tyre, including the inner edge, and look for cuts or bulges.Brakes: 4.8% of tests fail on brakes, against 3.9% for a typical car of the same age and mileage. Brake firmly on the test drive: the car should stop straight with no pulsing or grinding.Lights: 7.3% of tests fail on lights & electrics, against 6.6% for a typical car of the same age and mileage. Walk round the car with every light on, including brake, fog and number plate lights.Lights−0.7 ptsTyres: 3.8% of tests fail on tyres, against 5.1% for a typical car of the same age and mileage. Check the tread on every tyre, including the inner edge, and look for cuts or bulges.Tyres+1.3 ptsBrakes: 4.8% of tests fail on brakes, against 3.9% for a typical car of the same age and mileage. Brake firmly on the test drive: the car should stop straight with no pulsing or grinding.Brakes−0.9 ptsSuspension: 2.4% of tests fail on suspension, against 4.9% for a typical car of the same age and mileage. Listen for knocks over speed bumps and push each corner down: it should settle at once.Suspension+2.5 ptsExhaust: 1.5% of tests fail on emissions & leaks, against 1.4% for a typical car of the same age and mileage. Listen for a blowing exhaust at start-up and look underneath for oil or fluid leaks.Exhaust−0.2 ptsSuspension: 2.4% of tests fail on suspension, against 4.9% for a typical car of the same age and mileage. Listen for knocks over speed bumps and push each corner down: it should settle at once.Brakes: 4.8% of tests fail on brakes, against 3.9% for a typical car of the same age and mileage. Brake firmly on the test drive: the car should stop straight with no pulsing or grinding.Tyres: 3.8% of tests fail on tyres, against 5.1% for a typical car of the same age and mileage. Check the tread on every tyre, including the inner edge, and look for cuts or bulges.Lights: 7.3% of tests fail on lights & electrics, against 6.6% for a typical car of the same age and mileage. Walk round the car with every light on, including brake, fog and number plate lights.Exhaust: 1.5% of tests fail on emissions & leaks, against 1.4% for a typical car of the same age and mileage. Listen for a blowing exhaust at start-up and look underneath for oil or fluid leaks.Lights: 7.3% of tests fail on lights & electrics, against 6.6% for a typical car of the same age and mileage. Walk round the car with every light on, including brake, fog and number plate lights.Lights−0.7 ptsTyres: 3.8% of tests fail on tyres, against 5.1% for a typical car of the same age and mileage. Check the tread on every tyre, including the inner edge, and look for cuts or bulges.Tyres+1.3 ptsBrakes: 4.8% of tests fail on brakes, against 3.9% for a typical car of the same age and mileage. Brake firmly on the test drive: the car should stop straight with no pulsing or grinding.Brakes−0.9 ptsSuspension: 2.4% of tests fail on suspension, against 4.9% for a typical car of the same age and mileage. Listen for knocks over speed bumps and push each corner down: it should settle at once.Suspension+2.5 ptsExhaust: 1.5% of tests fail on emissions & leaks, against 1.4% for a typical car of the same age and mileage. Listen for a blowing exhaust at start-up and look underneath for oil or fluid leaks.Exhaust−0.2 pts
Better than typicalTypicalWorse than typical
Brakes: 4.8% of tests fail on brakes, against 3.9% for a typical car of the same age and mileage. Brake firmly on the test drive: the car should stop straight with no pulsing or grinding.

Every MOT area

Share of tests failing on each area, against a typical car of the same age and mileage (black line).

Lights & electrics
7.3% vs 6.6%
Brakes
4.8% vs 3.9%
Visibility
4.5% vs 3.8%
Tyres
3.8% vs 5.1%
Suspension
2.4% vs 4.9%
Seat belts & airbags
2.0% vs 0.4%
Body & structure
2.0% vs 1.4%
Emissions & leaks
1.5% vs 1.4%
Wheels
0.2% vs 0.2%
Steering
0.2% vs 0.9%

Buying one or MOT due? Check these

  • Brake performance 3.1× typical
    On the test drive, brake firmly: the car should stop straight with no pulsing through the pedal.
  • Exhaust emissions (catalyst) 3.0× typical
    Check past MOT emissions readings in the car's history: rising readings can mean catalyst or sensor problems.
  • Number plate lights 2.2× typical
    Walk around with the lights on: bulb failures are the easiest MOT fails to avoid.
  • Windscreen wipers
    Test the washers and wipers: a cheap fix, but a very common MOT fail.
  • Headlight aim
    Park facing a wall at night: both dipped beams should sit level and dip to the left.
  • Tyre damage & cracking
    Look for cuts, bulges and cracking on both sidewalls of every tyre.

Pass rate by mileage

First-time pass rate by mileage at the test.

50%60%70%80%90%100%0k10k20k30k40k50k60k70k80k90k100k110k93%84%79%72%66%61%
SEAT MiiTypical car

Most common MOT failures

ItemThis carTypicalvs typical
Windscreen wipers2.7%2.1%1.3×
Headlight aim2.6%2.0%1.3×
Brake performance2.1%0.7%3.1×
Tyre damage & cracking1.9%3.0%0.6×
Sidelights1.8%1.2%1.6×
Tyre tread depth1.7%1.7%1.0×
Airbag warning light1.7%0.2%8.4×
Windscreen washers1.5%1.5%1.0×
Number plate lights1.4%0.6%2.2×
Fuel cap/sealing device1.2%0.1%16.7×

Specific defects found

Tester wording for the most frequent failure items, per 1,000 tests.

Defectper 1,000
Wiper blade missing or obviously not clearing the windscreen26.6
The aim of a headlamp is not within limits laid down in the requirements25.7
Significant brake effort recorded with no brake applied indicating a binding brake17.7
Tyre tread depth not in accordance with the requirements17.3
An SRS malfunction indicator lamp (MIL) indicates a system malfunction16.7
A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning16.6
Windscreen washers not working or not providing sufficient fluid to clear the windscreen15.2
A tyre seriously damaged13.4
Check another car

Pick a make and model to see its MOT pass rate, best and worst years and weak spots.

Every year and engine

Tap a year to see its engines. Grades compare each car with cars of the same age and mileage (A = best 20% of cars on UK roads, E = worst 20%), so an older or higher-mileage car can grade above one with a higher pass rate.

2021 SEAT Mii1 engine86.7% passE
EngineTestsPass rateRankGrade
Electric3,19886.7%Beats 15%E
2020 SEAT Mii1 engine87.7% passD
EngineTestsPass rateRankGrade
Electric1,04287.7%Beats 20%D
2019 SEAT Mii1 engine87.3% passC
EngineTestsPass rateRankGrade
1.0 Petrol6,51887.3%Beats 42%C
2018 SEAT Mii1 engine84.6% passD
EngineTestsPass rateRankGrade
1.0 Petrol7,46484.6%Beats 26%D
2017 SEAT Mii1 engine83.1% passD
EngineTestsPass rateRankGrade
1.0 Petrol10,10783.1%Beats 27%D
2016 SEAT Mii1 engine79.7% passE
EngineTestsPass rateRankGrade
1.0 Petrol17,46779.7%Beats 19%E
2015 SEAT Mii1 engine80.0% passD
EngineTestsPass rateRankGrade
1.0 Petrol23,78980.0%Beats 40%D
2014 SEAT Mii1 engine79.9% passB
EngineTestsPass rateRankGrade
1.0 Petrol27,35779.9%Beats 63%B
2013 SEAT Mii1 engine74.9% passC
EngineTestsPass rateRankGrade
1.0 Petrol31,11074.9%Beats 55%C
2012 SEAT Mii1 engine73.2% passC
EngineTestsPass rateRankGrade
1.0 Petrol15,50973.2%Beats 59%C

FAQ

What is the SEAT Mii MOT pass rate?

79.1% of MOT tests on the SEAT Mii were passed first time, based on 143,561 tests between 2018 and 2026 of cars first registered 2012–2021. A typical car of the same age and mileage passes 79.4% of the time.

Is the SEAT Mii reliable?

On MOT results it rates C (average): it passes first time less often than a typical car of the same age and mileage and does better than 48% of cars on UK roads. MOT results cover safety and emissions items, not every kind of breakdown.

Which SEAT Mii year is best?

Among years with enough data, the 2014 Mii does best for its age and mileage: it beats 63% of cars on UK roads. The 2015 does worst: it beats 40%.

What are the most common MOT failures on the SEAT Mii?

The most common failure items are windscreen wipers, headlight aim, brake performance. Compared with similar cars, airbag warning light comes up 8.4× as often.

How we calculate this. We use official MOT results for cars tested in Great Britain from 2018 to 2026. Each car is compared with typical cars of the same age and mileage, so old and new cars are judged fairly; “pts” are percentage points above or below them. Differences also reflect how cars are used and maintained, not only how they are built.