Audi TT vs Mercedes-Benz SLK
On MOT-testable defects the Audi TT comes out ahead: 17.4% of its tests record a failure against 19.4% for the Mercedes-Benz SLK, a 2.0-point gap. The biggest single difference is emissions & environmental, where the TT records failures noticeably more often.
17.4%
TT fail rate
19.4%
SLK fail rate
2.03pp
Difference
Side by side
| Metric | Audi TT | Mercedes-Benz SLK |
|---|---|---|
| MOT tests analysed | 676,127 | 354,328 |
| Pass rate | 82.6% | 80.5% |
| Fail rate | 17.4% | 19.4% |
Where they differ
| Category | TT | SLK |
|---|---|---|
| Emissions & environmental | 3.3% | 0.0% |
| Suspension | 6.4% | 9.1% |
| Visibility | 0.0% | 2.6% |
| Brakes | 4.8% | 5.1% |
| Lighting & signalling | 7.3% | 7.0% |
| Tyres | 5.1% | 5.1% |
Methodology & source. 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.