Petrol Mercedes-Benz B-Class: MOT pass rate

75.2% of petrol Mercedes-Benz B-Class pass the MOT first time, measured across 19,996 DVSA tests on that fuel type alone. Average mileage at test was 71,194.

Petrol against the other Mercedes-Benz B-Class versions

Why the fuel type changes the number

Petrol cars avoid the DPF and emissions failures that catch diesels, and usually fail on the same consumables as any other car.

On the Mercedes-Benz B-Class specifically, electric is the strongest at 84.5%, and this petrol version sits 0 points above the 75.2% model average.

What it means if you are buying one

There is little to choose between fuel types on this model, so decide on running costs and mileage rather than MOT record. 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 petrol Mercedes-Benz B-Class had covered 71,194 miles at test, against 78,400 for the diesel and 45,186 for the electric. That is a shade above the middle of the range, still ordinary wear rather than a red flag, but worth checking against the service book for the car's age.

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 B-Class page separate age from fuel if you want to isolate one.

Most common MOT failures on a petrol Mercedes-Benz B-Class

1. A direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, 2.4% of tests (3.62x the national rate for this defect)
2. A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, 4.8% of tests (3.15x the national rate for this defect)
3. Lamp emitted colour, position or intensity not in accordance with the requirements, 1.7% of tests (2.9x the national rate for this defect)
4. A suspension joint dust cover missing or no longer prevents the ingress of dirt etc, 4.5% of tests (2.45x the national rate for this defect)
5. Brake pipe damaged or excessively corroded, 2.6% of tests (2.44x the national rate for this defect)
6. Engine MIL illuminated indicating a malfunction, 2.3% of tests (1.79x the national rate for this defect)
7. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 2.9% of tests (1.75x the national rate for this defect)
8. A spring or spring component fractured or seriously weakened, 3.7% of tests (1.63x the national rate for this defect)
9. A tyre seriously damaged, 3.6% of tests (1.29x the national rate for this defect)
10. A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED, 1.5% of tests (1.23x the national rate for this defect)

From 20,110 DVSA-tracked petrol Mercedes-Benz B-Class tests, 2024, split out from the Mercedes-Benz B-Class's other fuel types. DVSA testers marked 4.59% 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 petrol Mercedes-Benz B-Class

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

1. A flexible brake hose excessively damaged, deteriorated, chafed, twisted or stretched, 3.1% of tests (5.51x the national rate for this defect)
2. Brake pipe damaged or excessively corroded, 16.4% of tests (2.66x the national rate for this defect), also fails
3. Lamp emitted colour, position or intensity not in accordance with the requirements, 2.9% of tests (2.09x the national rate for this defect), also fails
4. Brake disc or drum significantly and obviously worn, 4.5% of tests (1.42x the national rate for this defect)
5. A tyre seriously damaged, 20.1% of tests (1.3x the national rate for this defect), also fails
6. Tyre tread depth not in accordance with the requirements, 20% of tests
7. Brake disc or drum excessively weakened, insecure or fractured, 11.6% of tests
8. a brake lining or pad worn below 1.5mm, 9.4% of tests
9. A suspension pin, bush or joint excessively worn, 5.5% of tests
10. A spring or spring component fractured or seriously weakened, 4.1% of tests, also fails

From 20,110 DVSA-tracked petrol Mercedes-Benz B-Class tests, 2024.

Other Mercedes-Benz B-Class fuel types

• Diesel Mercedes-Benz B-Class - 75.1%
• Electric Mercedes-Benz B-Class - 84.5%

All Mercedes-Benz B-Class MOT data · Every model