Model Reports 8 min read Updated 11 Sep 2026 DVSA open data · 6,793 tests analysed

Mercedes-Benz B-Class 2013: reliability & common MOT faults

1,982 first-attempt MOT failures were recorded on the 2013 Mercedes-Benz B-Class in 2025. The items recorded most often on them were Linkage ball joint dust cover (front) and Tyres — Condition (front). Figures are among first-attempt failed MOT tests, not among all tests.

Petrol B-Class passed first time 7.8 pp more often than diesel ones (77.0% of 1,398 vs 69.2% of 5,395).

First-attempt pass

70.8%

of 6,793 first tests (2025)

First tests

6,793

test year 2025

Failed first attempts

1,982

failed first-attempt tests

Most common fail

13.3%

Linkage ball joint dust cover (front)

MOT pass rates

First-attempt and official-style rates among class 4 first tests of the year.

First-attempt pass

70.8%

of 6,793 first tests (2025)

Official-style pass

75.6%

incl. same-day PRS fixes

First tests

6,793

class 4 · first MOT of the year

Typical age 12.0 yrs · median mileage 79,804 mi

vs 2024: -0.5 pp first-attempt

Note:

  • Class 4 cars · first MOT of the year per vehicle · P/PRS/F outcomes (2025 data).
  • PRS (fixed at the station the same day) counts as a fail in the first-attempt rate.
  • Raw outcomes for this cohort — not adjusted for age, mileage, or peer mix.
  • MOT doesn't test engine or gearbox internals.

Common faults

Failure patterns that show up more often on this registration year than on similar cars.

These MOT failure patterns show up more often on this registration year than on similar cars of the same class, age, and mileage.

Shares below are measured across the 1,981 of 1,982 failed first attempts (99.9%) that recorded an odometer reading in 2025 — the subset the age-and-mileage comparison can be computed on.

Standout: Ball joint dust cover (front) — 6.4% of this year's failed first attempts

Recorded on 126 of those tests. It tops the table on elevation — about 5.2× more often than on similar cars of the same age and mileage. That is what makes it unusual for its class, which is a different question from what is most likely to fail; the buying checklist ranks by that. The full ranked list is in the table below.

Fault pattern Location Failures vs similar cars Share of fails Confidence
Road Wheels — Condition (front)
Road Wheels > Condition
 Front 45 ×17 2.3% Likely
Ball joint dust cover (front)
Suspension > Anti-roll bars > Ball joint dust cover
 Front 126 ×5.2 6.4% Strong
SRS malfunction indicator lamp
Seat belts and supplementary restraint systems > SRS malfunction indicator lamp
 Any 118 ×4.3 6.0% Likely
Linkage ball joint dust cover (front)
Suspension > Anti-roll bars > Linkage ball joint dust cover
 Front 264 ×4.3 13.3% Likely
Coil spring (rear)
Suspension > Springs > Coil springs > Coil spring
 Rear 246 ×2.8 12.4% Possible
Registration plate lamp(s) (rear)
Lamps, reflectors and electrical equipment > Registration plate lamp(s)
 Rear 164 ×2.6 8.3% Possible

Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and about 2.0× more often than similar cars).

Note: Rates and comparisons are among first-attempt failed tests, not all MOTs. Patterns come from MOT defect codes — not manufacturer service bulletins, recalls, or a diagnosis of any individual car. Failures and advisories are listed separately.

If you are buying one

What this year's MOT record means for the decision in front of you.

On this year, prefer the petrol. The diesel cars passed first time 7.8 pp less often, on 5,395 tests.

Other B-Class years worth knowing about

Newer cars always pass more often, so a plain "best year" list would just rank by age. These are the years that beat or miss the trend their own neighbouring years set — the only age-adjusted signal this data supports.

Year vs the years either side First-attempt pass (rises with newer cars) First tests
2012 B-Class +4.6 pp better 69.2% 5,571
2011 B-Class -5.2 pp worse 58.4% 3,257
2014 B-Class -2.2 pp worse 71.5% 7,934

What to check on a 2013 B-Class

The items that failed 2013 B-Class most often, as a share of the year's failed first attempts. This is what goes wrong, not what is unusual — the table further up the page covers that.

  • Linkage ball joint dust cover (front) — recorded on 13.3% of failed first attempts
  • Tyres — Condition (front) — recorded on 13.0% of failed first attempts
  • Coil spring (rear) — recorded on 12.4% of failed first attempts
  • Registration plate lamp(s) — recorded on 8.3% of failed first attempts
  • Ball joint dust cover (front) — recorded on 6.4% of failed first attempts

Every figure here is a first-attempt MOT rate from DVSA open data for this model line. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

FAQs

Short answers about how to read this model-year guide.

Petrol B-Class passed first time 7.8 pp more often than diesel ones (77.0% of 1,398 vs 69.2% of 5,395). In 2025, 70.8% of 6,793 first MOTs on the 2013 Mercedes-Benz B-Class passed first time (PRS — items fixed at the station the same day — counted as a fail). The official-style rate including PRS is 75.6%. Among 1,982 failed first-attempt MOT tests (test year 2025), Ball joint dust cover (front) appears more often t…
Ranked by how often they were actually recorded, the items that failed 2013 Mercedes-Benz B-Classs most often at the first attempt were Linkage ball joint dust cover (front) (13.3%), Tyres — Condition (front) (13.0%) and Coil spring (rear) (12.4%) — each as a share of the year's failed first attempts. That is what goes wrong on the car. It is a different question from which patterns are unusual for the class, which…
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Ball joint dust cover (front) (6.4% of those tests; 126 observed failures; about 5.2× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Ball joint dust cover (front) shows up more often than on similar cars (6.4% of those tests; 126 observed failures; about 5.2× more often than similar cars). That does not prove a design fault — age, mileage, and how the car was used still matter. Treat it as a pre-purchase check point, not a manufacturer service bulletin.
Common MOT problem areas for the 2013 Mercedes-Benz B-Class include Ball joint dust cover (front), Road Wheels — Condition (front), SRS malfunction indicator lamp. These patterns show up more often than on similar cars after we filter out sparse noise — not a full list of every possible fault on an individual car.
This page highlights MOT failure patterns for the 2013 Mercedes-Benz B-Class (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics — not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars — not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics — this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces — but does not remove — differences in how cars were used and maintained.
  • We never invent pass rates, star scores, or ranks when those data marts are missing.

Contains public sector information licensed under the Open Government Licence v3.0.

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