Mercedes-benz B-class Reliability, MOT Pass Rate & Common Faults
Free Mercedes-benz B-class car check
Is the Mercedes-benz B-class reliable? We analysed 984,871 real MOT tests across 77,700 vehicles to find out.
Got a specific Mercedes-benz B-class? Enter the reg for a free check:
The Mercedes-benz B-class is above average for reliability based on real UK MOT data. Here's everything you need to know before buying a used Mercedes-benz B-class.
Mercedes-benz B-class Number Plates
Number plates registered to a Mercedes-benz B-class. Click on any registration for full vehicle details — including MOT history, mileage records, previous owners and damage history.
Mercedes-benz B-class MOT Pass Rate by Year
How likely is a Mercedes-benz B-class to pass its MOT? Here's the pass rate for each registration year, newest first.
Mercedes-benz B-class Problems — What Goes Wrong?
The most common reasons a Mercedes-benz B-class fails its MOT, ranked by how often they occur. Check for these problems before you buy.
Mercedes-benz B-class Common Faults & Problems
These are the most common serious faults found on Mercedes-benz B-class models during MOT testing — flagged as dangerous or major failures that need immediate attention.
Mercedes-benz B-class Mileage — What's Normal?
How many miles does a typical Mercedes-benz B-class owner drive per year? Use this to check if a car you're looking at has suspiciously low or high mileage.
Mercedes-benz B-class MOT Data by Registration Year
Full breakdown of pass rate and mileage for each year. Use this to compare the Mercedes-benz B-class year you're looking at.
| Year | Tests | Pass Rate | Low Mi. | Typical Mi. | High Mi. |
|---|---|---|---|---|---|
| 2020 | 60 | 88.3% | 19,737 | 31,908 | 40,453 |
| 2019 | 3,108 | 90.8% | 15,459 | 24,389 | 36,698 |
| 2018 | 23,783 | 88.0% | 18,559 | 28,461 | 42,438 |
| 2017 | 43,066 | 87.3% | 23,105 | 35,198 | 51,853 |
| 2016 | 43,849 | 86.2% | 25,398 | 39,170 | 58,114 |
| 2015 | 55,146 | 85.1% | 29,026 | 44,396 | 64,789 |
| 2014 | 93,846 | 83.3% | 32,920 | 50,060 | 71,645 |
| 2013 | 90,807 | 82.8% | 34,502 | 53,364 | 77,436 |
| 2012 | 82,753 | 81.4% | 36,629 | 57,090 | 82,130 |
| 2011 | 62,680 | 76.2% | 36,576 | 56,113 | 79,895 |
| 2010 | 87,029 | 76.7% | 39,057 | 60,441 | 85,206 |
| 2009 | 94,934 | 76.4% | 41,142 | 63,922 | 90,002 |
| 2008 | 91,763 | 75.6% | 43,310 | 67,852 | 94,774 |
| 2007 | 88,030 | 75.4% | 42,814 | 67,664 | 96,075 |
| 2006 | 93,843 | 74.8% | 44,424 | 69,513 | 96,645 |
| 2005 | 26,496 | 74.9% | 44,688 | 69,803 | 96,986 |
How Long Does a Mercedes-benz B-class Last?
Based on 77,700 Mercedes-benz B-class vehicles on UK roads.
Mercedes-benz B-class Mileage Distribution
Total mileage recorded across all Mercedes-benz B-class MOT tests. If the car you're looking at is above the 75th percentile, it's done more miles than most.
Best Year to Buy a Used Mercedes-benz B-class
Based on MOT pass rates across all registration years with sufficient test data.
90.8% MOT pass rate from 3,108 tests
74.8% MOT pass rate from 93,843 tests
The best year to buy a used Mercedes-benz B-class is 2019, which has the highest MOT pass rate at 90.8% across 3,108 tests. The 2006 model year has the lowest pass rate at 74.8% — if you're looking at one from that year, budget for potential repairs and get a thorough pre-purchase inspection.
How Does the Mercedes-benz B-class Compare?
MOT pass rates compared to similar models. Click any model for the full breakdown.
| Model | Pass Rate | Tests | Typical Mileage | Lifespan |
|---|---|---|---|---|
| Mercedes-benz B-class THIS CAR | 79.4% | 984,871 | 56,084 mi | 21 yrs |
| Mercedes-benz C | 77.6% | 8,031,355 | 77,082 mi | 32 yrs |
| Mercedes-benz E | 79.4% | 4,722,746 | 83,960 mi | 33 yrs |
| Mercedes-benz A-class | 77.6% | 4,204,702 | 57,023 mi | 28 yrs |
| Skoda Citigo | 84.9% | 492,537 | 35,113 mi | 14 yrs |
Compared to the Mercedes-benz C (77.6% pass rate) and the Mercedes-benz E (79.4% pass rate), the Mercedes-benz B-class sits in the middle of the pack on MOT reliability.
Found a Mercedes-benz B-class you like?
Run a full vehicle history check on the specific car. See finance, stolen, write-off, mileage and MOT data for that exact vehicle.
Check a specific Mercedes-benz B-classShould you buy a used Mercedes-benz B-class?
The Mercedes-benz B-class has an overall MOT pass rate of 79.4% across 984,871 real MOT tests — comfortably above the UK average, which puts it among the more reliable models on UK roads.
The most common failure point is tyre tread depth below requirements of 1.6mm with 6,159 recorded occurrences. Check for this on any test drive or pre-purchase inspection.
On the safety side, the most frequently flagged dangerous fault is tyre tread depth below requirements of 1.6mm. Dangerous faults cause an immediate MOT failure and mean the vehicle is not roadworthy until repaired. If you're viewing a Mercedes-benz B-class with an expired or recently passed MOT, ask the seller whether any dangerous faults were found and fixed during the last test.
A typical Mercedes-benz B-class owner drives around 5,590 miles per year. If the car you're looking at is significantly above this, expect more wear on suspension, brakes and tyres. If it's well below, the vehicle may have been sitting unused — check for perished rubber, corroded discs and stale fluids.
In terms of longevity, most Mercedes-benz B-class models stay on UK roads for around 21 years — a strong showing that suggests solid build quality and readily available parts. If you're buying one that's already approaching that window, the data suggests it has plenty of life left provided it's been maintained.
Before committing to a purchase, we recommend running a full vehicle history check on the specific car. This will reveal any outstanding finance, stolen markers, write-off history and mileage discrepancies that the seller may not disclose — and that the MOT data alone can't tell you.