Does the Porsche 928 fail the MOT on noise, emissions and leaks more than it should?
The Porsche 928 records 6.00 noise, emissions and leaks failure items per 100 initial MOT tests (2019–2024), against 7.34 expected for a car of the same age mix: less than expected for its class and age (−1.34, 95% interval −2.09 to −0.59). It ranks 477 of 678 models on noise, emissions and leaks (1 = most failures above expected).
Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · all models on noise, emissions and leaks · check a Porsche 928 by registration
What exactly fails on noise, emissions and leaks?
The most frequent DVSA defect wording in this group on the Porsche 928 is “Emissions levels exceed default limits”, recorded 137 times in 2019–2024.
| DVSA defect wording | Items | Per 100 tests |
|---|---|---|
| Emissions levels exceed default limits | 137 | 2.74 |
| Lambda coefficient outside the default limits or the range specified by the manufacturer | 86 | 1.72 |
Source: DVSA MOT bulk data (OGL v3.0) · Window: 2019–2024 · n = 5,000 (initial tests) · Method: failure items (major and minor) grouped by DVSA's defect tree; wordings with 30+ items · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV
If a Porsche 928 gets a noise, emissions and leaks advisory, how often does it fail next time?
5.5% of Porsche 928 MOTs with a noise, emissions and leaks advisory were followed by a fail in the same group at the next MOT, typically 12.6 months and 183 miles later (510 advisories followed).
Source: DVSA MOT bulk data (OGL v3.0) · Window: 2019–2024 · n = 510 (advisories followed) · Method: the same vehicles followed to their next ordinary MOT · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV
Other pages for this model
Porsche 928 by postcode area · Porsche 928 body, chassis and structure failures · Porsche 928 brakes failures · Porsche 928 vehicle identification failures · Porsche 928 lamps, reflectors and electrics failures · Porsche 928 seat belts and airbags failures · Porsche 928 steering failures · Porsche 928 suspension failures · Porsche 928 tyres failures · Porsche 928 visibility failures