2017 Porsche Cayman — MOT failures & pass rate
The 2017 Porsche Cayman passed 95.1% of its 4,725 recorded MOT tests. Coupes & convertibles of a similar age fail 9.8% of the time, so this is 4.9pp better than the group it competes with. Failures cluster in tyres, visibility and lighting & signalling.
What the MOT record shows
No single area dominates — tyres (3.1%) and visibility (1.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are tread depth, washers and registration plates — tread depth alone was recorded 95 times.
A 60-90k example is materially riskier than a 0-30k one: 11.5% versus 3.8%.
Advisories point at the next bill rather than this one: tyres was flagged on 16.2% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 3.1% | 149 |
| 2 | Visibility | 1.1% | 54 |
| 3 | Lighting & signalling | 0.9% | 43 |
| 4 | Other defects | 0.4% | 21 |
| 5 | Brakes | 0.4% | 21 |
| 6 | Emissions & environmental | 0.3% | 13 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 95 |
| 2 | Washers | 41 |
| 3 | Registration plates | 35 |
| 4 | Headlamp aim | 32 |
| 5 | Tyre pressure monitoring system | 26 |
| 6 | Wipers | 19 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 16.2% | 766 |
| 2 | Brakes | 4.9% | 231 |
| 3 | Other defects | 2.2% | 106 |
| 4 | Visibility | 1.7% | 80 |
| 5 | Suspension | 1.6% | 76 |
| 6 | Body, structure & corrosion | 0.6% | 30 |
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 | 2,841 | 3.8% |
| 30-60k | 1,714 | 6.1% |
| 60-90k | 156 | 11.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 994 | 4.3% |
| 2022 | 954 | 4.2% |
| 2023 | 924 | 4.3% |
| 2024 | 938 | 6.6% |
| 2025 | 915 | 5.0% |
What to check before buying a 2017 Cayman
On a 2017 Cayman, tyres is what the MOT record says goes wrong most — it appeared in 3.1% of tests. Check these areas before you commit.
- Tyres (3.1% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Visibility (1.1% 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.
- Lighting & signalling (0.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£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 2017 Porsche Caymans pass their MOT?
95.1% of the 4,725 2017 Porsche Cayman MOT tests in this dataset passed — a 4.9% fail rate.
What is the most common MOT failure on a 2017 Porsche Cayman?
Tyres, recorded in 3.1% of tests, followed by visibility (1.1%).
Does the 2017 Cayman get worse with mileage?
Its MOT fail rate rises from 3.8% in the 0-30k band to 11.5% in the 60-90k band.
Methodology & source. Based on 4,725 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.