2018 MG MG3 — MOT failures & pass rate
14,644 MOT tests on the 2018 MG MG3 are in this dataset, and 86.0% of them passed. That is 2.8 percentage points worse than superminis of a similar age, which fail at 11.2%. Failures cluster in tyres, lighting & signalling and brakes.
What the MOT record shows
No single area dominates — tyres (6.1%) and lighting & signalling (5.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, wipers and tread depth — headlamp aim alone was recorded 684 times.
Mileage is the strongest signal on the record: 9.5% of 0-30k cars fail, rising to 32.6% once past 90-120k — 3.4× the risk.
Tyres is the most common advisory, noted on 23.2% of tests — work that passed today but is likely due soon.
The trend is worsening — 9.5% of tests failed in 2021 against 18.3% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.1% | 888 |
| 2 | Lighting & signalling | 5.5% | 805 |
| 3 | Brakes | 4.8% | 696 |
| 4 | Visibility | 3.2% | 473 |
| 5 | Suspension | 2.7% | 393 |
| 6 | Seat belts & restraints | 1.5% | 222 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 684 |
| 2 | Wipers | 316 |
| 3 | Tread depth | 314 |
| 4 | Coil spring | 258 |
| 5 | Washers | 251 |
| 6 | Rbt (sp) | 234 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 23.2% | 3,398 |
| 2 | Brakes | 16.9% | 2,477 |
| 3 | Suspension | 8.0% | 1,174 |
| 4 | Other defects | 8.0% | 1,166 |
| 5 | Visibility | 2.6% | 382 |
| 6 | Emissions & environmental | 1.4% | 197 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 8,146 | 9.5% |
| 30-60k | 5,526 | 18.6% |
| 60-90k | 862 | 24.8% |
| 90-120k | 95 | 32.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 2,794 | 9.5% |
| 2022 | 2,871 | 11.5% |
| 2023 | 2,965 | 14.6% |
| 2024 | 2,968 | 15.6% |
| 2025 | 3,046 | 18.3% |
What to check before buying a 2018 MG3
The failure pattern for this year is specific enough to inspect against: tyres accounted for 6.1% of tests. Start there.
- Tyres (6.1% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Lighting & signalling (5.5% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (4.8% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2018 MG MG3s pass their MOT?
86.0% of the 14,644 2018 MG MG3 MOT tests in this dataset passed — a 14.0% fail rate.
What is the most common MOT failure on a 2018 MG MG3?
Tyres, recorded in 6.1% of tests, followed by lighting & signalling (5.5%).
Does the 2018 MG3 get worse with mileage?
Its MOT fail rate rises from 9.5% in the 0-30k band to 32.6% in the 90-120k band.
Methodology & source. Based on 14,644 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.