334,841 tests in 2025
Mercedes-Benz C-Class reliability and MOT pass rate
78.4% passed first time. The 21.6% fail rate is 1.0 points better than the all-car average, on a median example 10 years old with 83,842 miles.
MOT pass rates / Mercedes-Benz
Pass rate
78.4%
22.6% of all cars failed; 21.6% of these did.
Fixed on the day
3.9%
Passed after a defect was put right during the visit.
Median at test
83,842 mi
10 years old.
Fail rate by age
| Age at test | Tests | Fail rate |
|---|---|---|
| 3-5 years | 18,992 | 11.4% |
| 6-9 years | 119,610 | 15% |
| 10-13 years | 101,476 | 23.3% |
| 14+ years | 94,451 | 30.1% |
What the C-Class fails on
Share of failed tests with at least one fail item in each DVSA inspection section. A test can fail in several sections at once.
- Suspension1,973 dangerous47.8%
- Tyres27,013 dangerous33.4%
- Brakes8,444 dangerous27.3%
- Lamps, reflectors and electrical equipment106 dangerous17.4%
- Noise, emissions and leaks93 dangerous13.7%
- Visibility30 dangerous8.7%
- Body, chassis, structure221 dangerous4.6%
- Seat belts and supplementary restraint systems3 dangerous3.9%
Is the C-Class getting worse?
The fail rate rose 1.3 points to 21.9% from 2022 to 2025 while the median one tested aged 2 years. Ageing alone would predict about 5.2 points, so it is holding up better than the fleet average for its age.
| Year | Tests | Median age | Fail rate | All cars | |
|---|---|---|---|---|---|
| 2022 | 396,618 | 9 | 20.6% | 22.5% | |
| 2023 | 385,809 | 9 | 21.3% | 22.8% | |
| 2024 | 321,828 | 10 | 22.3% | 23.2% | |
| 2025 | 321,702 | 11 | 21.9% | 22.6% |
Fail rate is first attempts at class 4 tests. Median age is the age of a typical C-Class at its test that year, and it is the number to watch: across the whole fleet each extra year of age adds roughly 1.9 points to the fail rate, so a model whose age and fail rate rise together is simply getting older.
The exact defects that fail it
Every failure item DVSA recorded against a C-Class in 2025, counted by how many tests each one appeared on.
- 1Ball joint: ball joint excessively worn15,011 tests
- 2Tread depth: tread depth below requirements of 1.6mm9,956 tests
- 3Coil spring: fractured or broken9,115 tests
- 4Malfunction indicator lamp: inoperative or indicates a malfunction7,162 tests
- 5Condition: has ply or cords exposed5,678 tests
- 6Condition: has a cut in excess of the requirements deep enough to reach the ply or cords4,973 tests
- 7Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt4,450 tests
- 8Rbt (sp): efficiency below requirements4,389 tests
What wears out first
Advisories are the tester flagging wear that is still legal. A typical C-Class collects 2.66 of them per test, and these are the ones that come up most. Treat it as the running-repairs list for the next year or two.
- 1Tread depth: tread depth below requirements of 1.6mm61,259 tests
- 2Brake discs: in such a condition that it is seriously weakened27,536 tests
- 3Rigid brake pipes: excessively corroded26,635 tests
- 4Brake pads: less than 1.5 mm thick24,793 tests
- 5Ball joint: ball joint excessively worn19,768 tests
- 6Condition: has a tear, caused by separation or partial failure of its structure16,582 tests
- 7Pins and bushes: pin or bush excessively worn15,788 tests
- 8Engine oil leaks: leaking excessively from engine14,821 tests
Questions
What is the Mercedes-Benz C-Class MOT pass rate?
78.4% of the 334,841 Mercedes-Benz C-Class first-attempt MOTs in 2025 passed. The fail rate of 21.6% compares with 22.6% across all cars. A further 3.9% passed after a defect was fixed during the test visit.
What does a Mercedes-Benz C-Class usually fail on?
The single most common failure is "Ball joint: ball joint excessively worn", recorded on 15,011 failed tests, followed by "Tread depth: tread depth below requirements of 1.6mm" and "Coil spring: fractured or broken". By section, suspension appears in 47.8% of failures, tyres appears in 33.4% of failures, brakes appears in 27.3% of failures.
Does age change the odds?
Sharply. At 3 to 5 years old the fail rate was 11.4%; at 14+ years it was 30.1%. The median Mercedes-Benz C-Class tested in 2025 was 10 years old with 83,842 miles.
Is the Mercedes-Benz C-Class getting less reliable?
The fail rate rose 1.3 points to 21.9% from 2022 to 2025 while the median one tested aged 2 years. Ageing alone would predict about 5.2 points, so it is holding up better than the fleet average for its age.
First-attempt class 4 tests, 2025, from DVSA’s anonymised MOT data (OGL v3, retrieved 2026-09-12). DVSA records newer cars trim by trim; this page adds every C-Class trim together. Year-on-year figures come from the same DVSA extracts for 2026 and earlier years. Full method on the pass rates hub.
DVSA has published 151 safety recalls naming the Mercedes-Benz C-Class: Mercedes-Benz C-Class recalls.
Other Mercedes-Benz models
Checking a particular C-Class?
The odds above are the model. The car in front of you has its own record: every test, every advisory, the mileage at each one.
Due a test? Find an approved MOT station near you.