1987 Porsche 928 S — MOT failures & pass rate
344 MOT tests on the 1987 Porsche 928 S are in this dataset, and 83.1% of them passed. Against all cars of a similar age (20.6% fail rate), the 1987 928 S comes out 3.7pp better. Failures cluster in lighting & signalling, emissions & environmental and brakes.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 11.1% of tests against 5.2% for the next-worst category.
At component level the recurring items are rear fog lamp, headlamp aim and non catalyst emissions — rear fog lamp alone was recorded 17 times.
Mileage matters less than usual here: the 1987 928 S fails 14.3% of the time in the 60-90k band and 16.4% at 150k+, a spread of only 2.1 points.
Emissions & environmental is the most common advisory, noted on 23.3% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 22.1% in 2021 to 13.6% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 11.1% | 38 |
| 2 | Emissions & environmental | 5.2% | 18 |
| 3 | Brakes | 4.9% | 17 |
| 4 | Suspension | 3.5% | 12 |
| 5 | Body, structure & corrosion | 3.2% | 11 |
| 6 | Steering | 2.6% | 9 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rear fog lamp | 17 |
| 2 | Headlamp aim | 15 |
| 3 | Non catalyst emissions | 13 |
| 4 | Service brake performance | 9 |
| 5 | Flexible brake hoses | 9 |
| 6 | Washers | 9 |
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 | 23.3% | 80 |
| 2 | Suspension | 22.4% | 77 |
| 3 | Other defects | 13.1% | 45 |
| 4 | Brakes | 9.6% | 33 |
| 5 | Tyres | 8.7% | 30 |
| 6 | Body, structure & corrosion | 6.4% | 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 |
|---|---|---|
| 60-90k | 42 | 14.3% |
| 90-120k | 123 | 21.1% |
| 120-150k | 96 | 14.6% |
| 150k+ | 55 | 16.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 77 | 22.1% |
| 2022 | 68 | 16.2% |
| 2023 | 69 | 15.9% |
| 2024 | 71 | 15.5% |
| 2025 | 59 | 13.6% |
What to check before buying a 1987 928 S
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 11.1% of tests. Start there.
- Lighting & signalling (11.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (5.2% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Brakes (4.9% 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.
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 1987 Porsche 928 Ss pass their MOT?
83.1% of the 344 1987 Porsche 928 S MOT tests in this dataset passed — a 16.9% fail rate.
What is the most common MOT failure on a 1987 Porsche 928 S?
Lighting & signalling, recorded in 11.1% of tests, followed by emissions & environmental (5.2%).
Does the 1987 928 S get worse with mileage?
Its MOT fail rate rises from 14.3% in the 60-90k band to 16.4% in the 150k+ band.
Methodology & source. Based on 344 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.