Diesel Mercedes-Benz C: MOT pass rate

76.6% of diesel Mercedes-Benz Cs pass the MOT first time, measured across 222,223 DVSA tests on that fuel type alone. Average mileage at test was 95,767.

Diesel against the other Mercedes-Benz C versions

Why the fuel type changes the number

Diesels carry DPFs, EGR valves and stricter smoke limits, so emissions and exhaust faults account for failures petrol cars never see.

On the Mercedes-Benz C specifically, hybrid is the strongest at 87.6%, and this diesel version sits 1.4 points below the 78% model average.

What it means if you are buying one

The diesel Mercedes-Benz C fails more often than the model average, so budget for the items that catch this fuel type and treat a fresh MOT as worth paying for. Buying a damaged one? run it through the analyzer, check the exact car, decode the VIN and check the mileage before you bid.

Mileage is part of the answer

The average diesel Mercedes-Benz C had covered 95,767 miles at test, against 76,080 for the petrol and 66,318 for the hybrid. That is above average and into the range where cambelts and water pumps are due if they have not already been done, so ask for the service history rather than take the mileage on trust.

Fuel type and mileage are tangled together: diesels are usually bought by higher-mileage drivers, so some of any gap between fuels is the miles rather than the engine. The per-year figures on the Mercedes-Benz C page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel Mercedes-Benz C

1. Brake pipe damaged or excessively corroded, 2.7% of tests (2.49x the national rate for this defect)
2. A suspension joint dust cover missing or no longer prevents the ingress of dirt etc, 3.4% of tests (1.87x the national rate for this defect)
3. Engine MIL illuminated indicating a malfunction, 2.2% of tests (1.69x the national rate for this defect)
4. Tyre tread depth not in accordance with the requirements, 5.3% of tests (1.67x the national rate for this defect)
5. A suspension pin, bush or joint excessively worn, 7.9% of tests (1.58x the national rate for this defect)
6. A spring or spring component fractured or seriously weakened, 3.2% of tests (1.42x the national rate for this defect)
7. A tyre cords visible or damaged, 2.3% of tests (1.38x the national rate for this defect)
8. A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 0.8% of tests (1.3x the national rate for this defect)
9. Parking brake efficiency below minimum requirement, 1.6% of tests (1.24x the national rate for this defect)
10. A tyre seriously damaged, 3.2% of tests

From 223,816 DVSA-tracked diesel Mercedes-Benz C tests, 2024, split out from the Mercedes-Benz C's other fuel types. DVSA testers marked 6.81% of these flagged defects as "dangerous", against 5.11% nationally. See which fuel type fails on the most dangerous defects nationally for how that compares across the whole fleet.

Most common MOT advisories on a diesel Mercedes-Benz C

Flagged but doesn't fail the car, a different list from the failures above.

1. A wheel bearing with excessive play, 4% of tests (6.13x the national rate for this defect)
2. Brake pipe damaged or excessively corroded, 14.5% of tests (2.33x the national rate for this defect), also fails
3. A flexible brake hose excessively damaged, deteriorated, chafed, twisted or stretched, 1.1% of tests (1.95x the national rate for this defect)
4. Brake disc or drum significantly and obviously worn, 5.2% of tests (1.63x the national rate for this defect)
5. Tyre tread depth not in accordance with the requirements, 35.6% of tests (1.34x the national rate for this defect), also fails
6. A suspension pin, bush or joint excessively worn, 15.1% of tests, also fails
7. Brake disc or drum excessively weakened, insecure or fractured, 12.3% of tests
8. A tyre seriously damaged, 9.7% of tests, also fails
9. a brake lining or pad worn below 1.5mm, 9.5% of tests
10. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 4% of tests

From 223,816 DVSA-tracked diesel Mercedes-Benz C tests, 2024.

Other Mercedes-Benz C fuel types

• Petrol Mercedes-Benz C - 79.2%
• Hybrid Mercedes-Benz C - 87.6%

All Mercedes-Benz C MOT data · Every model