Mercedes Benz B Class MOT failures and reliability

In 2023 the Mercedes Benz B Class took 72,737 MOT tests in Britain and passed 73% of them first time, close to the national average of 71% for all cars. The figures below come from the DVSA's record of every test, so they show what testers actually found on these cars rather than what owners report.

MOT tests in 2023: 72,737
First-time pass rate: 73%
All cars: 71%

What the B Class fails on

Share of tests with at least one failure in each area, against the figure for all cars.

Lights and electrics9.9% (all cars 11.3%)
Suspension8.3% (all cars 9.0%)
Tyres6.8% (all cars 6.4%)
Brakes6.1% (all cars 6.8%)
Visibility4.0% (all cars 4.8%)
Body and structure3.0% (all cars 3.5%)
Exhaust and emissions2.9% (all cars 3.1%)
Seat belts and airbags1.5% (all cars 1.0%)

Most common failure items

Share of tests on which each item was recorded.

Coil spring: fractured or broken 3.6%
Malfunction indicator lamp: inoperative or indicates a malfunction 2.1%
Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt 2.0%
Suspension arms, ball joint: ball joint excessively worn 1.8%
Registration plate lamp(s): inoperative in the case of a single lamp or all lamps 1.8%
Tyres, condition: has a cut in excess of the requirements deep enough to reach the ply or cords 1.8%
Brake pads: less than 1.5 mm thick 1.7%
Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt 1.6%

Most common advisories

Tread depth: worn close to legal limit/worn on edge 15.9%
Tyres, condition: slightly damaged/cracking or perishing 9.6%
Brake discs: worn, pitted or scored, but not seriously weakened 7.7%
Brake pads: wearing thin 7.6%
Rigid brake pipes: corroded, covered in grease or other material 7.6%
Brake discs: worn, but not excessively 3.2%
Non-component advisories: Child Seat fitted not allowing full inspection of adult belt 2.5%
Tyres, condition: has a cut but not deep enough to reach the ply or cords 2.3%

Pass rate by year of registration

Older cars fail more often whatever the model, so compare a car with others of the same age.

First registered	Tests	Pass rate
2005	536	56%
2006	2,455	56%
2007	3,159	56%
2008	3,919	56%
2009	4,734	59%
2010	4,833	61%
2011	3,759	62%
2012	5,894	71%
2013	7,191	75%
2014	8,360	75%
2015	5,695	80%
2016	5,374	83%
2017	5,744	84%
2018	3,980	87%
2019	4,201	90%
2020	2,839	91%

Typical mileage by age

Average odometer reading at the MOT, by the car's age in years at the test.

Age at test	Average mileage
3 years	18,948 miles
4 years	23,144 miles
5 years	31,249 miles
6 years	40,696 miles
7 years	48,378 miles
8 years	56,772 miles
9 years	65,527 miles
10 years	71,794 miles
11 years	78,576 miles
12 years	78,545 miles
13 years	85,018 miles
14 years	91,713 miles
15 years	96,866 miles
16 years	99,494 miles
17 years	100,399 miles
18 years	102,477 miles

Check a particular B Class

Model figures tell you what to look out for. To see one car's own MOT history, mileage and tax, enter its registration.

Other Mercedes Benz models

Source: Department for Transport, Anonymised MOT tests and results, 2023, cars and light vans, normal tests only. Pass rates are first-time passes; a pass after repair at the test station counts as a fail. Contains public sector information licensed under the Open Government Licence v3.0.