1992 Porsche 911 — MOT failures & pass rate
1,052 MOT tests on the 1992 Porsche 911 are in this dataset, and 90.9% of them passed. That is 10.0 percentage points better than coupes & convertibles of a similar age, which fail at 19.1%. Failures cluster in lighting & signalling, emissions & environmental and visibility.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 7.1% of tests against 3.2% for the next-worst category.
At component level the recurring items are headlamp aim, catalyst emissions and position lamp — headlamp aim alone was recorded 54 times.
Mileage is the strongest signal on the record: 3.4% of 0-30k cars fail, rising to 10.0% once past 150k — 2.9× the risk.
Emissions & environmental is the most common advisory, noted on 11.5% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 13.0% in 2021 to 8.3% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 7.1% | 75 |
| 2 | Emissions & environmental | 3.2% | 34 |
| 3 | Visibility | 1.7% | 18 |
| 4 | Suspension | 1.3% | 14 |
| 5 | Body, structure & corrosion | 1.1% | 11 |
| 6 | Brakes | 0.9% | 10 |
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 | 54 |
| 2 | Catalyst emissions | 41 |
| 3 | Position lamp | 21 |
| 4 | Washers | 16 |
| 5 | Rear fog lamp | 15 |
| 6 | Joints | 11 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Emissions & environmental | 11.5% | 121 |
| 2 | Brakes | 7.0% | 74 |
| 3 | Suspension | 5.7% | 60 |
| 4 | Tyres | 4.9% | 51 |
| 5 | Lighting & signalling | 2.2% | 23 |
| 6 | Body, structure & corrosion | 2.1% | 22 |
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 | 118 | 3.4% |
| 30-60k | 211 | 8.5% |
| 60-90k | 204 | 3.9% |
| 90-120k | 288 | 12.5% |
| 120-150k | 181 | 13.8% |
| 150k+ | 50 | 10.0% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 177 | 13.0% |
| 2022 | 231 | 9.1% |
| 2023 | 228 | 10.1% |
| 2024 | 212 | 5.7% |
| 2025 | 204 | 8.3% |
What to check before buying a 1992 911
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 7.1% of tests. Start there.
- Lighting & signalling (7.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (3.2% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Visibility (1.7% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
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 1992 Porsche 911s pass their MOT?
90.9% of the 1,052 1992 Porsche 911 MOT tests in this dataset passed — a 9.1% fail rate.
What is the most common MOT failure on a 1992 Porsche 911?
Lighting & signalling, recorded in 7.1% of tests, followed by emissions & environmental (3.2%).
Does the 1992 911 get worse with mileage?
Its MOT fail rate rises from 3.4% in the 0-30k band to 10.0% in the 150k+ band.
Methodology & source. Based on 1,052 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.