2005 Porsche Boxster — MOT failures & pass rate
18,747 MOT tests on the 2005 Porsche Boxster are in this dataset, and 84.7% of them passed. That is 6.9 percentage points better than coupes & convertibles of a similar age, which fail at 22.3%. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (5.6%) and suspension (5.0%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are rigid brake pipes, catalyst emissions and coil spring — rigid brake pipes alone was recorded 797 times.
Mileage is the strongest signal on the record: 7.1% of 0-30k cars fail, rising to 25.5% once past 150k — 3.6× the risk.
Brakes is the most common advisory, noted on 27.6% 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 | 5.6% | 1,050 |
| 2 | Suspension | 5.0% | 936 |
| 3 | Brakes | 4.5% | 842 |
| 4 | Emissions & environmental | 4.2% | 793 |
| 5 | Tyres | 2.2% | 412 |
| 6 | Visibility | 1.8% | 334 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rigid brake pipes | 797 |
| 2 | Catalyst emissions | 670 |
| 3 | Coil spring | 631 |
| 4 | Headlamp aim | 625 |
| 5 | Wipers | 284 |
| 6 | Tread depth | 250 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 27.6% | 5,182 |
| 2 | Tyres | 18.2% | 3,413 |
| 3 | Suspension | 10.4% | 1,945 |
| 4 | Other defects | 8.1% | 1,518 |
| 5 | Lighting & signalling | 7.1% | 1,331 |
| 6 | Emissions & environmental | 4.5% | 839 |
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 | 961 | 7.1% |
| 30-60k | 4,805 | 10.3% |
| 60-90k | 7,451 | 16.0% |
| 90-120k | 4,337 | 19.9% |
| 120-150k | 985 | 20.2% |
| 150k+ | 200 | 25.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,876 | 15.2% |
| 2022 | 3,851 | 15.3% |
| 2023 | 3,762 | 15.5% |
| 2024 | 3,658 | 15.8% |
| 2025 | 3,600 | 14.9% |
What to check before buying a 2005 Boxster
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 5.6% of tests. Start there.
- Lighting & signalling (5.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (5.0% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Brakes (4.5% 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 2005 Porsche Boxsters pass their MOT?
84.7% of the 18,747 2005 Porsche Boxster MOT tests in this dataset passed — a 15.3% fail rate.
What is the most common MOT failure on a 2005 Porsche Boxster?
Lighting & signalling, recorded in 5.6% of tests, followed by suspension (5.0%).
Does the 2005 Boxster get worse with mileage?
Its MOT fail rate rises from 7.1% in the 0-30k band to 25.5% in the 150k+ band.
Methodology & source. Based on 18,747 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.