MOT performance
Mercedes-Benz B-Class MOT pass rate and common failures
Across 145,990 MOT tests of the Mercedes-Benz B-Class in 2023–2024, 73.0% passed first time. Allowing for age, mileage and fuel, Mercedes-Benz B-Classs failed about as often as comparable cars. The most common failure item was “coil spring: fractured or broken”, on 3.42% of tests.
145,990 MOT tests on 74,462 vehicles, 2023–2024 · Source: DVSA (Open Government Licence) · Analysis: 73 Auto
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| Figure | Value | Basis |
|---|---|---|
| First-time pass rate | 73.0% | ±0.2 pts (95%), n = 145,990 |
| Failures vs similar cars | 0.96× | same age, mileage and fuel = 1.00 |
| Tests with a dangerous defect | 7.5% | n = 145,990 |
| Average age at test | 9.5 years | n = 145,990 |
| Median mileage at test | 62,724 miles | n = 145,990 |
| Vehicles tested | 74,462 | 2023–2024 |
Where Mercedes-Benz B-Classs fail
The share of MOT tests that failed on each area, and how that compares with cars of the same age, mileage and fuel. Areas where the difference is large and clear link to their own page.
| Area | Tests failed on it | vs similar cars |
|---|---|---|
| Lights, reflectors and electrical | 10.0% | -6% |
| Suspension | 8.5% | -5% |
| Tyres | 6.9% | +9% |
| Brakes | 6.1% | -6% |
| Driver's view of the road | 4.0% | -10% |
| Body, chassis and structure | 3.0% | -8% |
| Noise, emissions and leaks | 3.0% | +5% |
| Seat belts and airbags | 1.5% | +63% |
| Road wheels | 0.7% | +102% |
| Steering | 0.4% | -78% |
| Registration plates and VIN | 0.3% | -13% |
Mercedes-Benz B-Class MOT pass rate by fuel: diesel vs petrol
Raw pass rates partly reflect how old each fuel's cars are; the adjusted column compares each with cars of the same age, mileage and fuel.
| Fuel | Tests | Average age | First-time pass | vs similar cars |
|---|---|---|---|---|
| Diesel | 94,290 | 9.4 yrs | 72.5% | -2% |
| Petrol | 50,385 | 9.9 yrs | 73.5% | -9% |
Mercedes-Benz B-Class MOT pass rate by generation
Generations by first-registration date against 73 Auto's catalogue (cars registered within three months of a changeover left out).
| Generation | Tests | Average age | First-time pass | vs similar cars |
|---|---|---|---|---|
| W246 (2011–2019) | 83,783 | 8.2 yrs | 77.6% | -10% |
| W247 (2019 on) | 13,467 | 3.1 yrs | 90.5% | -19% |
Most common failure items
| Item | Area | Share of tests |
|---|---|---|
| Coil spring: fractured or broken | Suspension | 3.42% |
| Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt | Body, chassis and structure | 2.06% |
| Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt | Suspension | 1.88% |
| Ball joint: ball joint excessively worn | Suspension | 1.87% |
| Condition: has a cut in excess of the requirements deep enough to reach the ply or cords | Tyres | 1.84% |
| Registration plate lamp(s): inoperative in the case of a single lamp or all lamps | Lights, reflectors and electrical | 1.83% |
| Brake pads: less than 1.5 mm thick | Brakes | 1.74% |
| Condition: has ply or cords exposed | Tyres | 1.60% |
| Washers: provides insufficient washer liquid | Driver's view of the road | 1.58% |
| Tread depth: tread depth below requirements of 1.6mm | Tyres | 1.57% |
Most common advisories
Advisories are items the tester expects to need attention soon; they don't fail the test.
| Item | Area | Share of tests |
|---|---|---|
| Tread depth: tread depth below requirements of 1.6mm | Tyres | 14.13% |
| Condition: has a tear, caused by separation or partial failure of its structure | Tyres | 9.88% |
| Brake discs: in such a condition that it is seriously weakened | Brakes | 7.99% |
| Brake pads: less than 1.5 mm thick | Brakes | 7.64% |
| Rigid brake pipes: excessively corroded | Brakes | 7.60% |
Pass rate by age
| Age at test (years) | Tests | First-time pass rate | Failures vs similar cars |
|---|---|---|---|
| 3-4 | 14,445 | 89.7% | -17% |
| 5-6 | 18,420 | 84.9% | -9% |
| 7-8 | 22,964 | 80.0% | -11% |
| 9-10 | 29,721 | 73.9% | -10% |
| 11-12 | 19,358 | 66.7% | -4% |
| 13-15 | 25,780 | 57.5% | +4% |
| 16+ | 11,430 | 55.5% | +3% |
Pass rate by registration year
| Registered | Tests | First-time pass rate | Failures vs similar cars |
|---|---|---|---|
| 2021 | 1,922 | 91.0% | 0.82× |
| 2020 | 5,984 | 91.0% | 0.80× |
| 2019 | 8,616 | 89.8% | 0.81× |
| 2018 | 7,974 | 86.5% | 0.91× |
| 2017 | 11,464 | 83.4% | 0.94× |
| 2016 | 10,757 | 81.8% | 0.89× |
| 2015 | 11,385 | 79.4% | 0.87× |
| 2014 | 16,658 | 74.7% | 0.92× |
| 2013 | 14,366 | 73.3% | 0.88× |
| 2012 | 11,852 | 70.6% | 0.88× |
| 2011 | 7,394 | 60.2% | 1.09× |
| 2010 | 9,527 | 59.3% | 1.05× |
| 2009 | 9,161 | 57.7% | 1.03× |
| 2008 | 7,470 | 55.5% | 1.05× |
| 2007 | 5,883 | 55.6% | 1.04× |
| 2006 | 4,545 | 55.9% | 1.01× |
| 2005 | 952 | 56.5% | 0.98× |
Years with fewer tests are shown for completeness; only years with enough tests have their own page.
Compared with similar models
Check a specific Mercedes-Benz B-Class
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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.