1989 Porsche 911 — MOT failures & pass rate
2,841 MOT tests on the 1989 Porsche 911 are in this dataset, and 89.1% of them passed. Coupes & convertibles of a similar age fail 17.4% of the time, so this is 6.5pp better than the group it competes with. Failures cluster in lighting & signalling, visibility and brakes.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 7.9% of tests against 3.5% for the next-worst category.
At component level the recurring items are headlamp aim, washers and rear fog lamp — headlamp aim alone was recorded 144 times.
Mileage is the strongest signal on the record: 6.3% of 0-30k cars fail, rising to 13.1% once past 150k — 2.1× the risk.
Suspension is the most common advisory, noted on 8.6% 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 | 7.9% | 225 |
| 2 | Visibility | 3.5% | 98 |
| 3 | Brakes | 2.3% | 64 |
| 4 | Emissions & environmental | 2.1% | 60 |
| 5 | Body, structure & corrosion | 1.5% | 43 |
| 6 | Suspension | 1.4% | 40 |
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 | 144 |
| 2 | Washers | 83 |
| 3 | Rear fog lamp | 66 |
| 4 | Position lamp | 50 |
| 5 | Non catalyst emissions | 48 |
| 6 | Headlamp | 47 |
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 | 8.6% | 243 |
| 2 | Emissions & environmental | 7.4% | 211 |
| 3 | Tyres | 7.2% | 206 |
| 4 | Brakes | 7.0% | 199 |
| 5 | Body, structure & corrosion | 2.3% | 64 |
| 6 | Other defects | 2.2% | 63 |
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 | 364 | 6.3% |
| 30-60k | 501 | 9.0% |
| 60-90k | 694 | 9.4% |
| 90-120k | 612 | 14.2% |
| 120-150k | 428 | 13.8% |
| 150k+ | 237 | 13.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 557 | 11.7% |
| 2022 | 585 | 11.3% |
| 2023 | 575 | 11.0% |
| 2024 | 549 | 9.3% |
| 2025 | 575 | 11.3% |
What to check before buying a 1989 911
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 7.9% of tests. Start there.
- Lighting & signalling (7.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (3.5% 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.
- Brakes (2.3% 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.
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 1989 Porsche 911s pass their MOT?
89.1% of the 2,841 1989 Porsche 911 MOT tests in this dataset passed — a 10.9% fail rate.
What is the most common MOT failure on a 1989 Porsche 911?
Lighting & signalling, recorded in 7.9% of tests, followed by visibility (3.5%).
Does the 1989 911 get worse with mileage?
Its MOT fail rate rises from 6.3% in the 0-30k band to 13.1% in the 150k+ band.
Methodology & source. Based on 2,841 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.