2018 MG ZS — MOT failures & pass rate
28,753 MOT tests on the 2018 MG ZS are in this dataset, and 86.5% of them passed. Against small SUVs of a similar age (9.9% fail rate), the 2018 ZS comes out 3.6pp worse. Failures cluster in brakes, lighting & signalling and tyres.
What the MOT record shows
No single area dominates — brakes (6.2%) and lighting & signalling (5.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp, headlamp aim and brake discs — headlamp alone was recorded 1,235 times.
Condition tracks the odometer closely. Failures run at 8.1% in the 0-30k band and 29.4% in the 120-150k band, a 21.3-point spread — more than double.
Tyres is the most common advisory, noted on 25.0% of tests — work that passed today but is likely due soon.
The trend is worsening — 8.0% of tests failed in 2021 against 17.7% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 6.2% | 1,773 |
| 2 | Lighting & signalling | 5.8% | 1,677 |
| 3 | Tyres | 4.9% | 1,404 |
| 4 | Suspension | 2.3% | 662 |
| 5 | Visibility | 2.0% | 574 |
| 6 | Emissions & environmental | 1.2% | 353 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp | 1,235 |
| 2 | Headlamp aim | 887 |
| 3 | Brake discs | 751 |
| 4 | Tread depth | 660 |
| 5 | Service brake performance | 649 |
| 6 | Brake pads | 544 |
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 | 25.0% | 7,178 |
| 2 | Brakes | 24.8% | 7,133 |
| 3 | Other defects | 8.3% | 2,380 |
| 4 | Suspension | 6.5% | 1,872 |
| 5 | Visibility | 2.5% | 706 |
| 6 | Emissions & environmental | 1.8% | 510 |
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 | 13,044 | 8.1% |
| 30-60k | 12,553 | 16.8% |
| 60-90k | 2,721 | 22.2% |
| 90-120k | 366 | 27.9% |
| 120-150k | 51 | 29.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 5,405 | 8.0% |
| 2022 | 5,611 | 10.7% |
| 2023 | 5,804 | 13.9% |
| 2024 | 5,892 | 16.8% |
| 2025 | 6,041 | 17.7% |
What to check before buying a 2018 ZS
The failure pattern for this year is specific enough to inspect against: brakes accounted for 6.2% of tests. Start there.
- Brakes (6.2% 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.
- Lighting & signalling (5.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (4.9% 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.
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 ZSs pass their MOT?
86.5% of the 28,753 2018 MG ZS MOT tests in this dataset passed — a 13.5% fail rate.
What is the most common MOT failure on a 2018 MG ZS?
Brakes, recorded in 6.2% of tests, followed by lighting & signalling (5.8%).
Does the 2018 ZS get worse with mileage?
Its MOT fail rate rises from 8.1% in the 0-30k band to 29.4% in the 120-150k band.
Methodology & source. Based on 28,753 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.