Ford S-Max vs Mercedes-Benz B-Class
On MOT-testable defects, the Mercedes-Benz B-Class (fail rate 18.2%) performed better than the Ford S-Max (22.7%) across comparable years. The biggest divergence was body, structure & corrosion, where the S-Max recorded failures more often.
22.7%
S-Max fail rate
18.2%
B-Class fail rate
4.52pp
Difference
Side by side
| Metric | Ford S-Max | Mercedes-Benz B-Class |
|---|---|---|
| MOT tests analysed | 482,969 | 429,942 |
| Pass rate | 77.3% | 81.8% |
| Fail rate | 22.7% | 18.2% |
Where they differ
| Category | S-Max | B-Class |
|---|---|---|
| Body, structure & corrosion | 4.5% | 0.0% |
| Visibility | 0.0% | 3.2% |
| Lighting & signalling | 10.9% | 8.2% |
| Tyres | 7.5% | 5.6% |
| Brakes | 5.7% | 5.0% |
| Suspension | 7.4% | 6.7% |
Methodology & source. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.