1994 Porsche 911 — MOT failures & pass rate
2,733 MOT tests on the 1994 Porsche 911 are in this dataset, and 90.2% of them passed. Coupes & convertibles of a similar age fail 19.5% of the time, so this is 9.7pp better than the group it competes with. Failures cluster in lighting & signalling, emissions & environmental and visibility.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 7.2% of tests against 2.3% for the next-worst category.
At component level the recurring items are headlamp aim, catalyst emissions and rear fog lamp — headlamp aim alone was recorded 69 times.
Mileage is the strongest signal on the record: 8.1% of 0-30k cars fail, rising to 13.9% once past 150k.
Emissions & environmental is the most common advisory, noted on 13.2% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 10.8% in 2021 to 8.0% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 7.2% | 196 |
| 2 | Emissions & environmental | 2.3% | 63 |
| 3 | Visibility | 1.7% | 47 |
| 4 | Brakes | 1.7% | 46 |
| 5 | Suspension | 1.6% | 43 |
| 6 | Tyres | 1.3% | 35 |
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 | 69 |
| 2 | Catalyst emissions | 66 |
| 3 | Rear fog lamp | 56 |
| 4 | Headlamp | 40 |
| 5 | Stop lamp | 39 |
| 6 | Position lamp | 39 |
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 | 13.2% | 360 |
| 2 | Tyres | 10.5% | 286 |
| 3 | Suspension | 8.3% | 227 |
| 4 | Brakes | 7.5% | 206 |
| 5 | Lighting & signalling | 3.0% | 82 |
| 6 | Other defects | 2.8% | 77 |
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 | 209 | 8.1% |
| 30-60k | 310 | 6.1% |
| 60-90k | 776 | 8.9% |
| 90-120k | 845 | 11.6% |
| 120-150k | 416 | 9.9% |
| 150k+ | 173 | 13.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 516 | 10.8% |
| 2022 | 575 | 9.2% |
| 2023 | 584 | 11.0% |
| 2024 | 542 | 10.2% |
| 2025 | 516 | 8.0% |
What to check before buying a 1994 911
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 7.2% of tests. Start there.
- Lighting & signalling (7.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (2.3% 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 1994 Porsche 911s pass their MOT?
90.2% of the 2,733 1994 Porsche 911 MOT tests in this dataset passed — a 9.8% fail rate.
What is the most common MOT failure on a 1994 Porsche 911?
Lighting & signalling, recorded in 7.2% of tests, followed by emissions & environmental (2.3%).
Does the 1994 911 get worse with mileage?
Its MOT fail rate rises from 8.1% in the 0-30k band to 13.9% in the 150k+ band.
Methodology & source. Based on 2,733 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.