2003 Porsche 911 — MOT failures & pass rate
The 2003 Porsche 911 passed 85.6% of its 14,560 recorded MOT tests. Coupes & convertibles of a similar age fail 22.6% of the time, so this is 8.1pp better than the group it competes with. Failures cluster in lighting & signalling, brakes and emissions & environmental.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 8.7% of tests against 3.9% for the next-worst category.
At component level the recurring items are rigid brake pipes, headlamp aim and position lamp — rigid brake pipes alone was recorded 593 times.
A 150k+ example is materially riskier than a 0-30k one: 21.2% versus 4.5%.
Brakes is the most common advisory, noted on 21.7% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 8.7% | 1,266 |
| 2 | Brakes | 3.9% | 571 |
| 3 | Emissions & environmental | 3.6% | 523 |
| 4 | Body, structure & corrosion | 2.9% | 430 |
| 5 | Tyres | 2.5% | 356 |
| 6 | Suspension | 2.3% | 339 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rigid brake pipes | 593 |
| 2 | Headlamp aim | 520 |
| 3 | Position lamp | 507 |
| 4 | Catalyst emissions | 483 |
| 5 | Headlamp | 438 |
| 6 | Joints | 272 |
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 | 21.7% | 3,154 |
| 2 | Tyres | 14.7% | 2,135 |
| 3 | Suspension | 9.5% | 1,380 |
| 4 | Lighting & signalling | 7.7% | 1,116 |
| 5 | Emissions & environmental | 5.4% | 790 |
| 6 | Body, structure & corrosion | 5.1% | 740 |
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 | 557 | 4.5% |
| 30-60k | 3,366 | 8.8% |
| 60-90k | 5,692 | 14.7% |
| 90-120k | 3,577 | 18.6% |
| 120-150k | 1,070 | 19.5% |
| 150k+ | 292 | 21.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,029 | 14.7% |
| 2022 | 2,922 | 14.0% |
| 2023 | 2,941 | 14.4% |
| 2024 | 2,878 | 14.7% |
| 2025 | 2,790 | 14.3% |
What to check before buying a 2003 911
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 8.7% of tests. Start there.
- Lighting & signalling (8.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (3.9% 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.
- Emissions & environmental (3.6% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 Porsche 911s pass their MOT?
85.6% of the 14,560 2003 Porsche 911 MOT tests in this dataset passed — a 14.4% fail rate.
What is the most common MOT failure on a 2003 Porsche 911?
Lighting & signalling, recorded in 8.7% of tests, followed by brakes (3.9%).
Does the 2003 911 get worse with mileage?
Its MOT fail rate rises from 4.5% in the 0-30k band to 21.2% in the 150k+ band.
Methodology & source. Based on 14,560 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.