Mercedes-Benz B-Class MOT Pass Rate
The Mercedes-Benz B-Class has an MOT pass rate of 80.4%, compared with a UK average of 79.1%, based on 12,325 DVSA MOT tests from 2004 to March 2026. It ranks 176th of 386 cars we track by pass rate.
The most common MOT problem area on the Mercedes-Benz B-Class is tyres, at 29.7% of all defects and advisories recorded.
Data: DVSA MOT test results, 2004 to March 2026. Last updated 3 October 2026.
- Mercedes-Benz B-Class MOT pass rate
- 80.4%
- UK average pass rate
- 79.1%
- MOT tests analysed
- 12,325
Ranked 176 of 386 models by MOT pass rate (1 is the highest).
What the Mercedes-Benz B-Class fails on
Every defect and advisory recorded at MOT, grouped by area. Includes advisories as well as failure items.
| Area | Share of all items | Items per 100 tests | Items recorded |
|---|---|---|---|
| Tyres | 29.7% | 48.4 | 5,962 |
| Brakes | 27.7% | 45 | 5,552 |
| Lights and signalling | 10.6% | 17.3 | 2,128 |
| Suspension | 9.6% | 15.6 | 1,925 |
| Other items | 8% | 13.1 | 1,611 |
| Bodywork | 4.8% | 7.8 | 965 |
| Windscreen and wipers | 4% | 6.4 | 793 |
| Corrosion | 1.4% | 2.2 | 277 |
| Steering | 1.2% | 2 | 243 |
| Exhaust and emissions | 1% | 1.7 | 208 |
| Fuel system | 0.8% | 1.3 | 162 |
| Electrical | 0.8% | 1.3 | 157 |
| Structure | 0.3% | 0.4 | 51 |
| Drivetrain | 0% | 0.1 | 8 |
Fail rate by mileage
How the Mercedes-Benz B-Class holds up as the miles build, using the odometer reading at each test.
| Mileage at test | B-Class fail rate | UK fail rate | Tests |
|---|---|---|---|
| Under 40,000 miles | 11.4% | 13.1% | 4,331 |
| 40,000 to 79,999 miles | 20.5% | 21.7% | 5,153 |
| 80,000 to 119,999 miles | 29.8% | 28.3% | 2,270 |
| 120,000 miles or more | 33.8% | 31.4% | 550 |
Which years to avoid
Fail rate by year first registered, next to the UK fail rate for all cars registered that year. Older cars fail more often whatever the model, so compare each year with its own UK figure.
| Year | B-Class fail rate | UK fail rate, same year | Tests |
|---|---|---|---|
| 2005 | 24.1% | 25.4% | 83 |
| 2006 | 25.3% | 25.3% | 604 |
| 2007 | 26.7% | 25.2% | 524 |
| 2008 | 27% | 25.3% | 877 |
| 2009 | 24.3% | 24.9% | 1,047 |
| 2010 | 22.2% | 24.5% | 1,137 |
| 2011 | 25.5% | 23.4% | 833 |
| 2012 | 17.9% | 22.6% | 1,098 |
| 2013 | 19.2% | 21.6% | 1,219 |
| 2014 | 16.1% | 20.2% | 1,682 |
| 2015 | 14% | 18.7% | 1,112 |
| 2016 | 14.3% | 17.3% | 848 |
| 2017 | 12.8% | 15.6% | 865 |
| 2018 | 13% | 14.7% | 339 |
| 2019 | 21.1% | 13.8% | 57 |
Years with fewer than 50 tests, and cars too new to have reached their first MOT, are left out.
Mercedes-Benz B-Class MOT questions
Is the Mercedes-Benz B-Class reliable?
On MOT results the Mercedes-Benz B-Class is better than average: it passes 80.4% of tests against a UK average of 79.1%, ranking 176th of 386 cars we track. Allowing for the age of the cars tested, its fail rate of 19.6% is 2 percentage points lower than the 21.6% you would expect from the average car of the same registration years. A pass rate is one useful signal of how well a model holds up, but it does not capture breakdowns between tests, repair costs or how an individual car has been looked after, so always check the history of the specific car.
What does the Mercedes-Benz B-Class usually fail its MOT on?
Across 12,325 MOT tests, the areas most often flagged on the Mercedes-Benz B-Class were tyres (29.7%), brakes (27.7%) and lights and signalling (10.6%), shown as a share of all defects and advisories recorded. These counts include advisories as well as failure items, so they show where problems tend to appear rather than only what caused a fail.
Does the Mercedes-Benz B-Class get worse with mileage?
Yes. The Mercedes-Benz B-Class fails 11.4% of MOT tests taken at under 40,000 miles and 33.8% at 120,000 miles or more, based on 4,331 and 550 tests respectively. Across all models the equivalent figures are 13.1% and 31.4%.
How does the Mercedes-Benz B-Class compare with the national average?
The Mercedes-Benz B-Class passes 80.4% of MOT tests, 1.3 percentage points above the UK average of 79.1% across all 6,681,613 tests in the data. That places it 176th of 386 cars with at least 1,000 tests, where 1st has the highest pass rate.
Check a specific Mercedes-Benz B-Class
See the full MOT history of the exact car you're looking at, free.
Related reading
What Does 'Brake Disc Worn' Mean on an MOT? Serious or Not?
Brake Disc Worn: Repair Cost and How Urgent Is It
Repeated Brake Disc Worn Advisory: Should You Walk Away?
What Does 'Suspension Arm Bush Worn' Mean on an MOT? Serious or Not?
Suspension Arm Bush Worn: Repair Cost and How Urgent Is It
Repeated Suspension Arm Bush Worn Advisory: Should You Walk Away?
What Does 'Rear Suspension Bush Worn' Mean on an MOT? Serious or Not?
Rear Suspension Bush Worn: Repair Cost and How Urgent Is It
Known problems to watch for
Other Mercedes-Benz models
Data: DVSA MOT test results for Great Britain, 2004 to March 2026, published under the Open Government Licence v3.0. Figures cover 12,325 tests. Last updated 3 October 2026. How these figures are calculated.
How to cite this data: Source: CarBuyerIQ analysis of DVSA MOT test data, https://www.carbuyeriq.com/mot-pass-rates/mercedes-benz/b-class