2015 Porsche 911 — MOT failures & pass rate
9,036 MOT tests on the 2015 Porsche 911 are in this dataset, and 95.6% of them passed. That is 7.5 percentage points better than coupes & convertibles of a similar age, which fail at 11.9%. Failures cluster in tyres, lighting & signalling and visibility.
What the MOT record shows
No single area dominates — tyres (2.1%) and lighting & signalling (1.2%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, tread depth and registration plates — headlamp aim alone was recorded 100 times.
Mileage is the strongest signal on the record: 3.3% of 0-30k cars fail, rising to 13.5% once past 90-120k — 4.1× the risk.
Advisories point at the next bill rather than this one: tyres was flagged on 11.9% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 2.1% | 186 |
| 2 | Lighting & signalling | 1.2% | 105 |
| 3 | Visibility | 0.8% | 74 |
| 4 | Other defects | 0.5% | 46 |
| 5 | Suspension | 0.4% | 35 |
| 6 | Emissions & environmental | 0.4% | 34 |
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 | 100 |
| 2 | Tread depth | 78 |
| 3 | Registration plates | 73 |
| 4 | Washers | 59 |
| 5 | Catalyst emissions | 28 |
| 6 | Wipers | 23 |
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 | 11.9% | 1,077 |
| 2 | Brakes | 3.4% | 307 |
| 3 | Other defects | 2.5% | 221 |
| 4 | Visibility | 1.3% | 117 |
| 5 | Suspension | 1.1% | 97 |
| 6 | Emissions & environmental | 0.6% | 55 |
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 | 5,079 | 3.3% |
| 30-60k | 3,520 | 5.5% |
| 60-90k | 365 | 8.2% |
| 90-120k | 52 | 13.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,904 | 4.4% |
| 2022 | 1,809 | 4.0% |
| 2023 | 1,785 | 4.2% |
| 2024 | 1,743 | 4.7% |
| 2025 | 1,795 | 4.6% |
What to check before buying a 2015 911
On a 2015 911, tyres is what the MOT record says goes wrong most — it appeared in 2.1% of tests. Check these areas before you commit.
- Tyres (2.1% 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.
- Lighting & signalling (1.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (0.8% 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 2015 Porsche 911s pass their MOT?
95.6% of the 9,036 2015 Porsche 911 MOT tests in this dataset passed — a 4.4% fail rate.
What is the most common MOT failure on a 2015 Porsche 911?
Tyres, recorded in 2.1% of tests, followed by lighting & signalling (1.2%).
Does the 2015 911 get worse with mileage?
Its MOT fail rate rises from 3.3% in the 0-30k band to 13.5% in the 90-120k band.
Methodology & source. Based on 9,036 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.