Diesel BMW 120: MOT pass rate

76.2% of diesel BMW 120s pass the MOT first time, measured across 34,275 DVSA tests on that fuel type alone. Average mileage at test was 105,582.

Diesel against the other BMW 120 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 BMW 120 specifically, petrol is the strongest at 80.4%, and this diesel version sits 0.8 points below the 77% 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 diesel BMW 120 had covered 105,582 miles at test, against 73,234 for the petrol. 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 BMW 120 page separate age from fuel if you want to isolate one.

Most common MOT failures on a diesel BMW 120

1. A flexible brake hose excessively damaged, deteriorated, chafed, twisted or stretched, 1.5% of tests (16.11x the national rate for this defect)
2. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 4.8% of tests (5.07x the national rate for this defect)
3. A wheel with a loose or missing wheel nut, bolt or stud, 1.3% of tests (4.1x the national rate for this defect)
4. Lamp emitted colour, position or intensity not in accordance with the requirements, 1.2% of tests (2.07x the national rate for this defect)
5. Windscreen washers not working or not providing sufficient fluid to clear the windscreen, 2.7% of tests (1.57x the national rate for this defect)
6. Tyre tread depth not in accordance with the requirements, 4.8% of tests (1.49x the national rate for this defect)
7. Parking brake efficiency below minimum requirement, 1.9% of tests (1.48x the national rate for this defect)
8. A tyre seriously damaged, 4.1% of tests (1.46x the national rate for this defect)
9. A tyre cords visible or damaged, 2.1% of tests (1.26x the national rate for this defect)
10. The aim of a headlamp is not within limits laid down in the requirements, 2.9% of tests (1.24x the national rate for this defect)

From 34,444 DVSA-tracked diesel BMW 120 tests, 2024, split out from the BMW 120's other fuel types. DVSA testers marked 6.22% 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 BMW 120

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, 12.4% of tests (22.04x the national rate for this defect), also fails
2. A shock absorber damaged to the extent that it does not function or showing signs of severe leakage, 10.4% of tests (2.65x the national rate for this defect), also fails
3. Lamp emitted colour, position or intensity not in accordance with the requirements, 3.3% of tests (2.41x the national rate for this defect), also fails
4. Tyre tread depth not in accordance with the requirements, 34.1% of tests (1.28x the national rate for this defect), also fails
5. Brake disc or drum significantly and obviously worn, 4% of tests (1.24x the national rate for this defect)
6. a brake lining or pad worn below 1.5mm, 11.3% of tests (1.21x the national rate for this defect)
7. A suspension pin, bush or joint excessively worn, 13.4% of tests
8. Brake disc or drum excessively weakened, insecure or fractured, 12.4% of tests
9. A tyre seriously damaged, 9.1% of tests, also fails
10. Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users, 6.2% of tests

From 34,444 DVSA-tracked diesel BMW 120 tests, 2024.

Other BMW 120 fuel types

• Petrol BMW 120 - 80.4%

All BMW 120 MOT data · Every model