MOT performance
Mercedes-Benz B-Class W246 (2011–2019): MOT pass rate and common failures
Of 83,783 MOT tests on the Mercedes-Benz B-Class W246 in 2023–2024 (cars first registered Jan 2012–Nov 2018, on average 8.2 years old at test), 77.6% passed first time. Allowing for age, mileage and fuel, the W246 failed 10% less often than comparable cars. Against the generation that replaced it, the W247, it fails 11% more often once age and mileage are allowed for (0.90× vs 0.81×).
83,783 MOT tests on 41,752 vehicles, 2023–2024 · Source: DVSA (Open Government Licence) · Analysis: 73 Auto
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| Figure | Value | Basis |
|---|---|---|
| First-time pass rate | 77.6% | ±0.3 pts (95%), n = 83,783 |
| All Mercedes-Benz B-Classs | 73.0% | n = 145,990 |
| Failures vs similar cars | 0.90× | same age, mileage and fuel = 1.00; Mercedes-Benz B-Class overall 0.96× |
| Tests with a dangerous defect | 7.2% | n = 83,783 |
| Average age at test | 8.2 years | n = 83,783 |
| On sale (catalogue) | 2011–2019 | Nov 2011 to Jan 2019 |
W246 against the other Mercedes-Benz B-Class generations
Newer generations are younger at test, so their raw pass rates are higher almost by default; the adjusted column compares each with cars of the same age, mileage and fuel.
| Generation | Tests | Average age | First-time pass | vs similar cars | Dangerous |
|---|---|---|---|---|---|
| W246 (2011–2019) | 83,783 | 8.2 yrs | 77.6% | -10% | 7.2% |
| W247 (2019 on) | 13,467 | 3.1 yrs | 90.5% | -19% | 2.7% |
Where the W246 differs
- Body, chassis and structure: the W246 failed 76% less often than the Mercedes-Benz B-Class overall, relative to comparable cars (0.22× vs 0.92×).
- Steering: the W246 failed 59% less often than the Mercedes-Benz B-Class overall, relative to comparable cars (0.09× vs 0.22×).
- Brakes: the W246 failed 37% less often than the Mercedes-Benz B-Class overall, relative to comparable cars (0.59× vs 0.94×).
- Driver's view of the road: the W246 failed 28% less often than the Mercedes-Benz B-Class overall, relative to comparable cars (0.65× vs 0.90×).
| Area | W246 (vs similar) | W247 (vs similar) |
|---|---|---|
| Tyres | 7.2% (+17%) | 4.7% (+14%) |
| Lights, reflectors and electrical | 7.2% (-11%) | 1.6% (-39%) |
| Suspension | 6.2% (-12%) | 0.4% (-49%) |
| Brakes | 3.2% (-41%) | 0.8% (-54%) |
| Driver's view of the road | 2.4% (-35%) | 1.6% (-47%) |
| Noise, emissions and leaks | 2.2% (+10%) | 0.3% (-62%) |
| Seat belts and airbags | 1.3% (+108%) | 0.8% (+166%) |
| Road wheels | 0.8% (+145%) | 0.1% (-40%) |
| Body, chassis and structure | 0.5% (-78%) | 0.1% (-57%) |
| Registration plates and VIN | 0.2% (-12%) | 0.2% (-21%) |
| Steering | 0.1% (-91%) | 0.0% (-78%) |
Most common Mercedes-Benz B-Class W246 failure items
| Item | Area | Share of tests |
|---|---|---|
| Registration plate lamp(s): inoperative in the case of a single lamp or all lamps | Lights, reflectors and electrical | 2.85% |
| Coil spring: fractured or broken | Suspension | 2.78% |
| Condition: has a cut in excess of the requirements deep enough to reach the ply or cords | Tyres | 1.91% |
| Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt | Suspension | 1.90% |
| Condition: has ply or cords exposed | Tyres | 1.82% |
Pass rate by age, by generation
At the same age, the generations can be compared directly.
| Age at test (years) | W246 pass rate (tests) | W247 pass rate (tests) |
|---|---|---|
| 3-4 | 86.7% (2,590) | 90.6% (9,065) |
| 5-6 | 84.5% (16,977) | 88.9% (530) |
| 7-8 | 80.0% (22,964) | — |
| 9-10 | 73.9% (29,711) | — |
| 11-12 | 70.5% (11,541) | — |
Registration years in the W246
How cars are assigned to a generation
DVSA records don't say which generation a car is, so 73 Auto assigns each test by first-registration date against its catalogue's on-sale dates for the W246 (Nov 2011 to Jan 2019). Cars registered within three months either side of a changeover are left out, because run-out stock of the old model and early cars of the new one are registered in the same months. Some cars near the edges may still be of the neighbouring generation.
Check a specific Mercedes-Benz B-Class W246
Enter a UK registration to see that car's own MOT history and what it is likely to cost to own. Your first check is free and shows the vehicle summary and its headline ownership cost. The category-by-category breakdown is part of a paid check.
UK number plate or 17-character VIN
About this data. These are MOT test results, not a measure of mechanical reliability: a car's MOT outcome reflects its condition on the day, which depends on how it has been maintained and driven as well as how it was built. Figures cover class 4 vehicles (cars and light vans), normal tests only (retests excluded), outcomes pass, fail and pass after rectification at the station; vehicles at least 2.5 years old at test. Tests from 2023-01-01 to 2024-12-30. “Compared with similar cars” means compared with the national rate for cars of the same age, mileage band and fuel. Contains public sector information licensed under the Open Government Licence v3.0. Makes and models are matched to 73 Auto's vehicle catalogue; tests that can't be matched are left out rather than guessed. See how the MOT figures are produced.