2021 Mercedes-Benz E-Class — MOT failures & pass rate
15,579 MOT tests on the 2021 Mercedes-Benz E-Class are in this dataset, and 90.0% of them passed. Executive cars of a similar age fail at 9.5%, so the 2021 E-Class sits squarely on the average. Failures cluster in tyres, road wheels and lighting & signalling.
What the MOT record shows
Tyres dominates the failure mix at 6.8% of all tests — 4.2 points clear of road wheels, so it is the first thing to check.
At component level the recurring items are tread depth, headlamp aim and registration plates — tread depth alone was recorded 273 times.
Mileage matters less than usual here: the 2021 E-Class fails 10.0% of the time in the 0-30k band and 6.8% at 150k+, a spread of only 3.2 points.
Fuel type barely separates them — diesel fails 9.9% of the time against 10.9% for hybrid.
Advisories point at the next bill rather than this one: tyres was flagged on 16.2% of tests without failing them.
The trend is worsening — 7.1% of tests failed in 2021 against 9.9% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.8% | 1,057 |
| 2 | Road wheels | 2.5% | 398 |
| 3 | Lighting & signalling | 1.0% | 157 |
| 4 | Visibility | 0.9% | 133 |
| 5 | Brakes | 0.6% | 90 |
| 6 | Suspension | 0.4% | 65 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 273 |
| 2 | Headlamp aim | 136 |
| 3 | Registration plates | 97 |
| 4 | Wipers | 77 |
| 5 | Brake pads | 72 |
| 6 | Ball joint | 55 |
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 | 16.2% | 2,523 |
| 2 | Brakes | 5.9% | 911 |
| 3 | Other defects | 3.4% | 530 |
| 4 | Visibility | 2.8% | 430 |
| 5 | Suspension | 1.9% | 291 |
| 6 | Road wheels | 0.9% | 145 |
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 | 6,320 | 10.0% |
| 30-60k | 6,270 | 11.3% |
| 60-90k | 1,898 | 8.0% |
| 90-120k | 643 | 6.5% |
| 120-150k | 257 | 7.4% |
| 150k+ | 191 | 6.8% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 12,381 | 9.9% |
| Hybrid | 2,395 | 10.9% |
| Petrol | 800 | 10.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 98 | 7.1% |
| 2022 | 309 | 3.2% |
| 2023 | 1,051 | 5.6% |
| 2024 | 7,049 | 11.2% |
| 2025 | 7,072 | 9.9% |
What to check before buying a 2021 E-Class
On a 2021 E-Class, tyres is what the MOT record says goes wrong most — it appeared in 6.8% of tests. Check these areas before you commit.
- Tyres (6.8% 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 (2.5% of tests): Damaged or corroded wheels, missing/loose fixings — generally a moderate fix. Typical repair: £80–£250.
- Lighting & signalling (1.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
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 2021 Mercedes-Benz E-Classs pass their MOT?
90.0% of the 15,579 2021 Mercedes-Benz E-Class MOT tests in this dataset passed — a 10.0% fail rate.
What is the most common MOT failure on a 2021 Mercedes-Benz E-Class?
Tyres, recorded in 6.8% of tests, followed by road wheels (2.5%).
Does the 2021 E-Class get worse with mileage?
Its MOT fail rate rises from 10.0% in the 0-30k band to 6.8% in the 150k+ band.
Methodology & source. Based on 15,579 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.