Mercedes-Benz E400d — MOT pass rate & failures
The Mercedes-Benz E400d recorded a 85.5% MOT pass rate across 2,194 tests in this dataset (model years 2018–2023), with tyres, road wheels and suspension its most common failure areas. Its 14.5% fail rate is lower than the 16.4% average across all Mercedes-Benz E-Class versions.
How it compares
By model year
| Year | Tests | Pass rate | Fail rate |
|---|---|---|---|
| 2019 | 540 | 87.8% | 12.2% |
| 2020 | 943 | 85.4% | 14.6% |
| 2021 | 516 | 82.0% | 18.0% |
| 2022 | 168 | 87.5% | 12.5% |
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 9.4% | 206 |
| 2 | Road wheels | 5.3% | 116 |
| 3 | Suspension | 1.4% | 31 |
| 4 | Lighting & signalling | 1.1% | 25 |
| 5 | Other defects | 0.5% | 12 |
| 6 | Brakes | 0.5% | 10 |
| 7 | Emissions & environmental | 0.4% | 9 |
| 8 | Visibility | 0.3% | 7 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint | 33 |
| 2 | Headlamp aim | 29 |
| 3 | Registration plates | 18 |
| 4 | Tread depth | 16 |
| 5 | Malfunction indicator lamp | 9 |
| 6 | Brake pads | 8 |
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 | 12.5% | 275 |
| 2 | Brakes | 7.6% | 167 |
| 3 | Suspension | 4.9% | 107 |
| 4 | Other defects | 2.8% | 62 |
| 5 | Visibility | 2.2% | 49 |
| 6 | Road wheels | 0.6% | 14 |
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 | 939 | 13.5% |
| 30-60k | 1,013 | 15.5% |
| 60-90k | 193 | 15.0% |
| 90-120k | 38 | 10.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 170 | 10.0% |
| 2023 | 467 | 14.6% |
| 2024 | 702 | 16.8% |
| 2025 | 852 | 13.6% |
What to check before buying a Mercedes-Benz E400d
Focus on the areas it most often fails on — and remember MOT data covers testable defects only, not engine or gearbox health.
- Tyres (9.4% 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.
- Road wheels (5.3% of tests): Damaged or corroded wheels, missing/loose fixings — generally a moderate fix. Typical repair: £80–£250.
- Suspension (1.4% 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.
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 reliable is the Mercedes-Benz E400d at MOT time?
85.5% of the 2,194 Mercedes-Benz E400d MOT tests in this dataset passed — a 14.5% fail rate, better than the 16.4% average across all E-Class versions.
What is the most common MOT failure on a Mercedes-Benz E400d?
Tyres, recorded in 9.4% of tests, followed by road wheels (5.3%).
Does the E400d get worse with mileage?
Its MOT fail rate rises from 13.5% in the 0-30k band to 10.5% in the 90-120k band.
Methodology & source. Based on 2,194 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-06. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.