Mercedes-Benz B MOT Pass Rate & Official DVSA Failure Statistics

Mercedes-Benz B MOT History and Failure Rates vs UK National Average

The Mercedes-Benz B passed on its first attempt in 92.7%, and its overall record sits +12.2 percentage points above the national average for all cars. These figures come from every recorded DVSA MOT test for the Mercedes-Benz B in the 2023–2025 data: 3,185 tests across 4 model years (2019–2022). A test still carries exactly one pass or fail verdict.

Figures are computed from every recorded DVSA test for this model in the 2023–2025 data.

Most Common Mercedes-Benz B MOT Problems by Failure Category

Every MOT failure a tester records belongs to one inspection section of the DVSA manual. For the Mercedes-Benz B, the Tyres section leads the record — the breakdown below shows where the recorded failures cluster, then the exact strings behind the three biggest sections.

Shares are over the Mercedes-Benz B's recorded defect strings, merged across its year pages.

Top Recorded Mercedes-Benz B DVSA MOT Test Statistics & Defect Descriptions

The descriptions below are the exact DVSA failure strings testers recorded most often for the Mercedes-Benz B, each with how many of the model's 3,185 tests it was noted on.

• "Has a cut in excess of the requirements deep enough to reach the ply or cords" (Major) — noted on about 77 Mercedes-Benz B tests, 2.4% of the model's MOT record.
• "Windscreen damaged but not adversely affecting driver's view" (Minor) — noted on about 56 Mercedes-Benz B tests, 1.8% of the model's MOT record.
• "Wipers blade defective" (Minor) — noted on about 44 Mercedes-Benz B tests, 1.4% of the model's MOT record.
• "Has ply or cords exposed" (Major) — noted on about 31 Mercedes-Benz B tests, 1.0% of the model's MOT record.
• "Wipers does not clear the windscreen effectively" (Rectified) — noted on about 21 Mercedes-Benz B tests, 0.7% of the model's MOT record.
• "Headlamp aim too low" (Rectified) — noted on about 14 Mercedes-Benz B tests, 0.4% of the model's MOT record.

Best and Worst Mercedes-Benz B Model Years by Pass Rate

The strongest Mercedes-Benz B model year on record is 2019 (95.2% across 357 tests), and the weakest is 2021 (92.2%). The gap between them is 3.0 points. Years with fewer than 50 recorded tests are excluded, so these are the years with enough MOT history to mean something.

Mercedes-Benz B reliability is declining in the DVSA data — the pass rate moves about 0.8 points a year across the most recent model years shown above.

Newest model year first. Only years with at least 50 recorded tests are listed.

Pre-MOT Inspection Checklist for Mercedes-Benz B Owners

These checks follow this Mercedes-Benz B's own most-recorded failure strings, starting with what a tester is most likely to flag on a Mercedes-Benz B.

• the windscreen — “windscreen damaged”

  Check the driver’s side of the screen within the swept area for chips and cracks; anything larger than 10mm in the driver’s central view is a fail. Most chips can be resin-repaired for far less than a new screen.

• the wipers and washers — “wipers blade defective”

  Run the wipers with the screen wet: they should clear it in one sweep without smearing or juddering. Top the washer bottle up and check both jets hit the screen.

• the lights — “headlamp aim too low”

  Switch everything on and walk round the car: both headlamps on dip and main, every indicator, both brake lights, reverse, fog and the two number-plate lamps. A bulb is a few pounds and a five-minute job.

Derived from the DVSA failure strings testers recorded for the Mercedes-Benz B. A check that finds nothing means the item is likely fine, not that the test is guaranteed.

Frequently Asked Questions: Mercedes-Benz B MOT & Reliability