Mercedes-Benz 420 MOT pass rate
84.1% of 1,556 Mercedes-Benz 420 MOT tests pass.
The 420's pass rate of 84.1% is in line with the average across all Mercedes-Benz models, at 83.5%.
The Mercedes-Benz 420 has a pass rate of 84.1%, a little higher than the national average for cars (79.2%).
Own this Mercedes-Benz 420?
This is the average across every Mercedes-Benz 420 in the dataset. Look up your own registration for its actual MOT history, and a free place to keep its maintenance records.
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Pass rate by vehicle age
| Vehicle age | Pass rate | Tests | Average mileage |
|---|---|---|---|
| 0–3 years | no tests recorded | 0 | no reading |
| 3–6 years | no tests recorded | 0 | no reading |
| 6–10 years | no tests recorded | 0 | no reading |
| 10–15 years | too few tests (2) | 2 | no reading |
| 15+ years | 84.0% | 1,554 | 102,325 miles |
Common MOT failure reasons for the Mercedes-Benz 420
The most common reason the Mercedes-Benz 420 fails its MOT is lamps, reflectors and electrical equipment — present in 72.4% of failed tests, most often logged as "Not working".
| Category | Share of failed tests | Example |
|---|---|---|
| Lamps, reflectors and electrical equipment | 72.4% | Not working |
| Brakes | 46.3% | Excessively binding |
| Suspension | 45.6% | Ball joint dust cover no longer prevents the ingress of dirt |
| Body, chassis, structure | 28.6% | Has a major leak of exhaust gases |
| Visibility | 26.5% | Does not clear the windscreen effectively |
| Noise, emissions and leaks | 17.3% | Emissions carbon monoxide content excessive |
| Tyres | 9.5% | Has a tear, caused by separation or partial failure of its structure |
| Steering | 9.5% | Ball joint dust cover excessively damaged or deteriorated so that it no longer prevents the ingress of dirt |
| Identification of the vehicle | 6.1% | Does not conform to the specified requirements |
| Road Wheels | 4.8% | More than one fixing missing |
Related Mercedes-Benz models
- Mercedes-Benz 500 — 87.0% pass rate
- Mercedes-Benz 230 — 77.9% pass rate
- Mercedes-Benz 280 — 82.2% pass rate
- Mercedes-Benz 220 — 78.9% pass rate
- Mercedes-Benz Eqv — 89.4% pass rate
- Mercedes-Benz S 350 L Grand — 93.2% pass rate
Frequently asked questions
- What is the MOT pass rate for the Mercedes-Benz 420?
- 84.1% of Mercedes-Benz 420 MOT tests pass, based on 1,556 tests in the DVSA anonymised MOT tests and results dataset.
- What are the most common MOT failures for the Mercedes-Benz 420?
- The most common reason the Mercedes-Benz 420 fails its MOT is lamps, reflectors and electrical equipment — present in 72.4% of failed tests, most often logged as "Not working".
- Does this show the Mercedes-Benz 420's service history?
- No — this is MOT test data, which covers roadworthiness, not servicing. A service history is a separate record of maintenance work, which a specific car only has if its owner has kept it. See the Mercedes-Benz service history guide for how to check and keep one.