2003 MG ZS — MOT failures & pass rate
2,111 MOT tests on the 2003 MG ZS are in this dataset, and 69.9% of them passed. Against small SUVs of a similar age (28.2% fail rate), the 2003 ZS comes out 1.9pp worse. Failures cluster in brakes, lighting & signalling and suspension.
What the MOT record shows
One area stands out: brakes, recorded in 15.8% of tests against 12.1% for the next-worst category.
At component level the recurring items are rbt (sp), component mounting prescribed areas and service brake performance — rbt (sp) alone was recorded 202 times.
Condition tracks the odometer closely. Failures run at 17.9% in the 0-30k band and 39.8% in the 150k+ band, a 21.9-point spread — more than double.
Brakes is the most common advisory, noted on 39.4% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 31.6% in 2021 to 29.0% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 15.8% | 334 |
| 2 | Lighting & signalling | 12.1% | 256 |
| 3 | Suspension | 11.4% | 241 |
| 4 | Body, structure & corrosion | 11.1% | 234 |
| 5 | Emissions & environmental | 5.1% | 108 |
| 6 | Visibility | 4.6% | 97 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rbt (sp) | 202 |
| 2 | Component mounting prescribed areas | 182 |
| 3 | Service brake performance | 128 |
| 4 | Headlamp aim | 121 |
| 5 | Joints | 88 |
| 6 | Integral vehicle structure condition | 82 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 39.4% | 831 |
| 2 | Suspension | 33.0% | 697 |
| 3 | Body, structure & corrosion | 21.6% | 456 |
| 4 | Tyres | 21.1% | 446 |
| 5 | Other defects | 14.3% | 302 |
| 6 | Emissions & environmental | 10.6% | 224 |
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 | 67 | 17.9% |
| 30-60k | 379 | 23.8% |
| 60-90k | 705 | 30.2% |
| 90-120k | 618 | 31.1% |
| 120-150k | 242 | 35.9% |
| 150k+ | 98 | 39.8% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 1,945 | 30.1% |
| Diesel | 166 | 30.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 570 | 31.6% |
| 2022 | 468 | 29.5% |
| 2023 | 412 | 30.6% |
| 2024 | 354 | 28.8% |
| 2025 | 307 | 29.0% |
What to check before buying a 2003 ZS
The failure pattern for this year is specific enough to inspect against: brakes accounted for 15.8% of tests. Start there.
- Brakes (15.8% 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.
- Lighting & signalling (12.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (11.4% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
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 2003 MG ZSs pass their MOT?
69.9% of the 2,111 2003 MG ZS MOT tests in this dataset passed — a 30.1% fail rate.
What is the most common MOT failure on a 2003 MG ZS?
Brakes, recorded in 15.8% of tests, followed by lighting & signalling (12.1%).
Does the 2003 ZS get worse with mileage?
Its MOT fail rate rises from 17.9% in the 0-30k band to 39.8% in the 150k+ band.
Methodology & source. Based on 2,111 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.