At a glance
How 2,692 first tests went in 2025.
- Passed first time
- 88 in every 100
- Did not pass first time
- 12 in every 100326 failed first-attempt tests
- The typical car
- 3 yearsabout 24,088 miles
- First tests counted
- 2,692
What failed most often
- Tyre condition (front)18 in every 100 failed tests
- Headlight aim (front)17 in every 100 failed tests
How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.
These are patterns across 2022 MG 4 vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. A wear pattern follows age and use more than the way the car was built. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.
Tyres
One wear pattern: tyre tread depth (rear), 4.6 times as often as on similar cars.
Figures below are measured across the 326 failed first attempts in 2025 that had a mileage recorded, which allows a like-for-like comparison.
We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.
Tyre tread depth (rear)
What it means
Only primary grooves count when tread depth is assessed: those holding the wear indicators, or cut as deep as those when new. Shallower secondary grooves are ignored. Tread depth below the minimum for the vehicle is Dangerous, and so is a pattern not visible over the whole tread, but that second row applies only to vehicles that need the lower minimum.
Also noted as an advisory
Testers also noted it as an advisory, worn but not yet failing, on 68 first tests, 2.3 times as often as on similar cars.
Data: UK MOT open data, 2025. Compared with cars of the same age and mileage. Advisories count notes recorded on failed first tests only.
Lamps and electrical
One wear pattern: headlight aim (front), 3.2 times as often as on similar cars.
Headlight aim (front)
What it means
Beam aim too high, too low or off to either side is Major. Where a driver's beam aim control is fitted, the aim is tested without altering the setting, and rechecked at the highest setting only if it would fail for being too low. Masks or converter kits on right hand dip headlamps are acceptable.
Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.
Advisories
Other things testers noted as worn or close to failing, more often than on similar cars.
An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail. Advisories for the faults above are shown with those faults.
Suspension arm pins and bushes (front)
Brake discs (rear)
Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.
MOT pass rates
How first tests ended, and how the pass rates are counted.
- Passed first time
- 88in every 100
- Passed on the first test.
- Fixed at the station
- 5in every 100
- Failed, then fixed at the test station the same day.
- Failed
- 7in every 100
- Did not pass, and were not fixed at the test station.
First-attempt pass 87.9% of 2,692 first tests (2025): only cars that passed first time count. Official-style pass 92.6%: cars fixed at the test station also count as a pass. The 5 fixed and the 7 not fixed make the 12 in every 100 that did not pass first time.
If you are buying one
What this year's MOT record means for the decision in front of you.
Mileage matters most on a 2022 MG 4.
Of 2022 MG 4 vehicles with under 15,000 miles, 93 in every 100 passed their 2025 MOT first time. With 36,000 miles or more, 81 in every 100 did.
What to check at your mileage
How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.
| Under 15,000 | 21,000–27,000 | 36,000 and over | |
|---|---|---|---|
| Tyre condition (front) | 0.4 | 1.5 | 5.0 |
| Headlight aim (front) | 2.2 | 2.2 | 1.8 |
Faults per 100 first tests, by the car's mileage at the test.
Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.
FAQs
Short answers about how to read this model-year guide.
About this data
How this page is built and what it can (and can't) say.
These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.
What we include
UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.
Same-day repairs
PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.
How we compare
We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.
What this does not cover
- MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
- Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
- Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
- If the data for a car is too thin to say anything useful, we say so rather than guess.
Contains public sector information licensed under the Open Government Licence v3.0.
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