2014 Mercedes-Benz C-Class — MOT failures & pass rate
Across 153,870 MOT tests, the 2014 Mercedes-Benz C-Class recorded an 84.2% pass rate. Executive cars of a similar age fail at 15.5%, so the 2014 C-Class sits squarely on the average. Failures cluster in tyres, suspension and brakes.
What the MOT record shows
No single area dominates — tyres (6.8%) and suspension (5.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are tread depth, ball joint and headlamp aim — tread depth alone was recorded 6,902 times.
Condition tracks the odometer closely. Failures run at 8.1% in the 0-30k band and 19.8% in the 150k+ band, a 11.7-point spread — more than double.
Split by fuel, diesel examples fail 3.8pp more often than petrol ones (16.4% vs 12.6%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: tyres was flagged on 25.7% of tests without failing them.
The trend is worsening — 13.3% of tests failed in 2021 against 18.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.8% | 10,398 |
| 2 | Suspension | 5.5% | 8,515 |
| 3 | Brakes | 4.4% | 6,813 |
| 4 | Lighting & signalling | 3.4% | 5,282 |
| 5 | Emissions & environmental | 2.3% | 3,545 |
| 6 | Visibility | 1.6% | 2,484 |
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 | 6,902 |
| 2 | Ball joint | 3,849 |
| 3 | Headlamp aim | 3,647 |
| 4 | Malfunction indicator lamp | 3,092 |
| 5 | Coil spring | 3,005 |
| 6 | Brake pads | 2,707 |
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 | 25.7% | 39,594 |
| 2 | Brakes | 19.0% | 29,278 |
| 3 | Suspension | 12.3% | 18,986 |
| 4 | Other defects | 5.8% | 8,862 |
| 5 | Visibility | 3.8% | 5,782 |
| 6 | Emissions & environmental | 2.5% | 3,892 |
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 | 4,904 | 8.1% |
| 30-60k | 37,046 | 11.9% |
| 60-90k | 55,467 | 15.8% |
| 90-120k | 35,230 | 18.6% |
| 120-150k | 14,241 | 19.4% |
| 150k+ | 6,951 | 19.8% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 126,440 | 16.4% |
| Petrol | 27,402 | 12.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 30,858 | 13.3% |
| 2022 | 31,038 | 14.5% |
| 2023 | 31,184 | 16.0% |
| 2024 | 30,693 | 17.1% |
| 2025 | 30,097 | 18.0% |
What to check before buying a 2014 C-Class
On a 2014 C-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.
- Suspension (5.5% 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.
- Brakes (4.4% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
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 2014 Mercedes-Benz C-Classs pass their MOT?
84.2% of the 153,870 2014 Mercedes-Benz C-Class MOT tests in this dataset passed — a 15.8% fail rate.
What is the most common MOT failure on a 2014 Mercedes-Benz C-Class?
Tyres, recorded in 6.8% of tests, followed by suspension (5.5%).
Does the 2014 C-Class get worse with mileage?
Its MOT fail rate rises from 8.1% in the 0-30k band to 19.8% in the 150k+ band.
Methodology & source. Based on 153,870 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.