1980 Porsche 911 — MOT failures & pass rate
Across 265 MOT tests, the 1980 Porsche 911 recorded an 84.5% pass rate. That is 3.1 percentage points worse than coupes & convertibles of a similar age, which fail at 12.4%. Failures cluster in lighting & signalling, brakes and visibility.
What the MOT record shows
Lighting & signalling dominates the failure mix at 9.4% of all tests — 4.1 points clear of brakes, so it is the first thing to check.
At component level the recurring items are headlamp, headlamp aim and service brake performance — headlamp alone was recorded 18 times.
Mileage matters less than usual here: the 1980 911 fails 12.7% of the time in the 60-90k band and 14.8% at 120-150k, a spread of only 2.1 points.
Advisories point at the next bill rather than this one: suspension was flagged on 10.9% of tests without failing them.
The trend is worsening — 11.4% of tests failed in 2021 against 15.2% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 9.4% | 25 |
| 2 | Brakes | 5.3% | 14 |
| 3 | Visibility | 3.4% | 9 |
| 4 | Suspension | 3.4% | 9 |
| 5 | Emissions & environmental | 2.3% | 6 |
| 6 | Body, structure & corrosion | 2.3% | 6 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp | 18 |
| 2 | Headlamp aim | 14 |
| 3 | Service brake performance | 13 |
| 4 | Washers | 9 |
| 5 | Position lamp | 8 |
| 6 | Rear fog lamp | 6 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 10.9% | 29 |
| 2 | Brakes | 9.8% | 26 |
| 3 | Emissions & environmental | 9.4% | 25 |
| 4 | Tyres | 4.5% | 12 |
| 5 | Steering | 3.4% | 9 |
| 6 | Seat belts & restraints | 3.0% | 8 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 60-90k | 71 | 12.7% |
| 90-120k | 63 | 22.2% |
| 120-150k | 61 | 14.8% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 70 | 11.4% |
| 2022 | 59 | 23.7% |
| 2023 | 40 | 12.5% |
| 2024 | 50 | 14.0% |
| 2025 | 46 | 15.2% |
What to check before buying a 1980 911
On a 1980 911, lighting & signalling is what the MOT record says goes wrong most — it appeared in 9.4% of tests. Check these areas before you commit.
- Lighting & signalling (9.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (5.3% 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.
- Visibility (3.4% 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 1980 Porsche 911s pass their MOT?
84.5% of the 265 1980 Porsche 911 MOT tests in this dataset passed — a 15.5% fail rate.
What is the most common MOT failure on a 1980 Porsche 911?
Lighting & signalling, recorded in 9.4% of tests, followed by brakes (5.3%).
Does the 1980 911 get worse with mileage?
Its MOT fail rate rises from 12.7% in the 60-90k band to 14.8% in the 120-150k band.
Methodology & source. Based on 265 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.