Pass rate
79.5%
Around average — 2.3 pts ahead of the 77.2% that cars this age and mileage manage.
Across 21,184 recorded tests.
Typical repair bill £26–£67
2012 Mercedes-Benz B-Class MOT pass rate
- 2012
- 4 trims combined
- typical 82,028 mi
Most common fault
Brakes
27.7% of faults · 20.9% nationally
mostly worn pads and discs, corroded pipes and a handbrake that will not hold.
Part only £25–£55 for Rigid brake pipes excessively corroded. What fitting it takes →
11.2 pts down across model years — 11.8% in 2005, 0.6% in 2016.
Which year to buy
- Best 2019 91.9% pass
- Avoid 2008 71.8% pass
Across the 15 years on record, a spread of 20.1 points. See every year →
- First-attempt pass
- 74.8%
- Typical mileage
- 82k mi
The 2012 Mercedes-Benz B-Class MOT pass rate is 79.5% of its MOT tests — 2.3 points ahead of what its age and mileage predict. Brakes is the biggest single reason it fails, at 27.7% of what testers record.
Check your postcode
MOT pass rates are national — type your postcode to see how Mercedes-Benz B-Class does in your corner of the country.
Expert verdict
Brakes: 1.3× the national share
Brakes make up 27.7% of everything recorded on the 2012 Mercedes-Benz B-Class, against 20.9% nationally — 6.8 points above. Have the discs and pads measured rather than glanced at, and ask whether the handbrake holds on a slope.
- When it fails, it costs. Only 25% of this model’s typical repairs come in under £30 in parts — the failures here tend to be the kind that need a garage rather than a bulb.
Written from this page's own figures: fault shares against the national composition, the like-for-like pass rate, and the priced repair list. How these are worked out
Watching a Mercedes-Benz B-Class? Get an email when these numbers change .
Every Mercedes-Benz B-Class first registered in 2012 is combined here — 4 trim and body variants in total — so the sample is as large as the DVSA data allows.
How does the 2012 Mercedes-Benz B-Class compare?
Cars of this age and mileage average 77.2%, so this figure is 2.3 points ahead of what its age and mileage predict. On a first attempt, before any retests, the figure drops to 74.8%. The median 2012 Mercedes-Benz B-Class in this dataset had covered 82,028 mi.
The most common fuel recorded here is Diesel — 72% of tests, with a 78.2% pass rate. Pass rates also shift with the test month: tests recorded October–March passed 79.1% of the time, April–September 80.0%.
The single most recorded failure item is "Linkage ball joint dust cover ball joint dust cover severely deteriorated", noted on 3.76% of tests.
- 21,184 recorded tests behind this page.
- 79.5% overall pass rate, 74.8% on a first attempt.
- Across every year of the Mercedes-Benz B-Class, the average is 79.9% — best year 2019 (91.9%), worst 2008 (71.8%).
Figures count every completed test on this vehicle-year in the dataset, including retests. See methodology for the exact definition.
This page's data
- Tests analysed
- 21,184
- Typical mileage (median)
- 82,028 mi
- Make and model
- Mercedes-Benz B-Class
- Updated
- 2026-11-05
Source: DVSA anonymised MOT test data (2023–2025), OGL v3.0.
Top part to budget for
Ball Joint
Usually a DIY or independent-garage job.
Does mileage affect the B-Class MOT pass rate?
Pass rate by odometer reading. Bar lengths start at 67% so small gaps stay visible.
Fuel type and reliability
Pass rate by fuel type. Diesel is the most common here (72% of tests).
Regional pass rates for the B-Class
| Region | Tests | Pass rate |
|---|---|---|
| South East | 5,321 | 81.1% |
| South West | 2,501 | 75.7% |
| East of England | 2,493 | 80.6% |
| North West | 2,453 | 78.8% |
| West Midlands | 1,928 | 80.8% |
| East Midlands | 1,543 | 80.2% |
| Yorkshire | 1,458 | 77.9% |
| London | 1,319 | 86.2% |
| Scotland | 877 | 73.1% |
| Wales | 831 | 77.4% |
| North East | 458 | 74.2% |
Regions come from the postcode area recorded at the test station. Areas on region borders are assigned to the region with the majority of their population.
What fails a 2012 B-Class
Everything a tester recorded on this vehicle, grouped into the inspection sections that produced it. The notch on each bar is the national share, so you can see at a glance whether this car is unusual or just ordinary.
A test can record several items, so these percentages do not add up to 100%. The exact strings, with prices, are in the full DVSA record at the bottom of this page.
Before your test
Three checks worth doing on a 2012 B-Class
These are not generic tips — they are the faults recorded most often on this exact model, rewritten as things you can check yourself. All three take about ten minutes and cost nothing.
-
Check the suspension joints 3.8% of tests
“linkage ball joint dust cover ball joint dust cover severely deteriorated”
With the car parked on level ground, rock the top of each front wheel in and out while someone watches the suspension arm. Clunks, or rubber boots split and greasy, are what testers record here.
-
Check the coil springs 3.2% of tests
“coil spring fractured or broken”
Look up inside each wheel arch with a torch, all the way round the spring. A snapped spring usually breaks at the very bottom coil, where a quick glance will not reach.
-
Check the windscreen 2.6% of tests
“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.
Shares are the proportion of tests on this vehicle that recorded the item, so they overlap: one test can record several.
What it costs to get a 2012 B-Class through its MOT
Across the 10 items that are recorded most often on this model, the average repair comes to £26–£67 — and 25% of those repairs are parts that cost under £30.
- Average repair across the 10 common items
- £26–£67
- Cheapest common item: malfunction indicator lamp inoperative or…
- £3–£12
- Dearest common item: windscreen damaged
- £80–£200
- Common items a careful owner can do at home
- 80%
- Repairs that still cost under £30
- 25%
Estimates from typical UK parts prices, weighted by how often each item appears in 21,184 MOT tests on this vehicle. They exclude diagnostics, retest fees and garage labour where the part is a DIY fit, and they are not figures from the DVSA dataset. Older and higher-mileage examples cost more than the average. How these estimates are built → · All MOT repair costs → · Cheapest cars to put through a test →
Every year of the B-Class, side by side
15 model years on record, from 2005 to 2019. Across them the pass rate runs from 71.8% to 91.9% — a spread of 20.1 points. The bar under each year is the item that failed it most often.
- 2005 71.9% joints constant velocity boot…
- 2006 72.3% joints constant velocity boot…
- 2007 72.3% joints constant velocity boot…
- 2008 71.8% joints constant velocity boot…
- 2009 73.4% joints constant velocity boot…
- 2010 74.0% joints constant velocity boot…
- 2011 74.4% side repeaters not working
- 2012 79.5%linkage ball joint dust cover…
- 2013 81.0% linkage ball joint dust cover…
- 2014 81.8% coil spring fractured or broken
- 2015 84.7% coil spring fractured or broken
- 2016 86.3% registration plate lamp(s)…
- 2017 87.1% registration plate lamp(s)…
- 2018 89.1% registration plate lamp(s)…
- 2019 91.9% has a cut in excess of the…
Colour is the pass rate on a fixed scale, so a block means the same thing on any model. Each year links to its own page with the full fault breakdown.
Compare the 2012 Mercedes-Benz B-Class with another year
The raw pass rate mostly measures age. The year comparison adds the like-for-like figure, the mileage bands and the repair bill.
Other 2012 cars with a similar record
- BMW 3 Series 79.4%
- Skoda Fabia 79.6%
- BMW 1 Series 79.4%
- BMW X1 79.4%
- Suzuki Alto 79.4%
- Mitsubishi Shogun 79.4%
Closest pass rates among 2012 cars with at least 2,000 tests, so a small sample cannot flatter itself into the list. See the full rankings: best and worst MOT pass rates.
The full DVSA record for the 2012 Mercedes-Benz B-Class 10 failure items · 6 advisories · 10 inspection categories · mileage brackets · all of it in the page, none of it above the fold
Every inspection category
Shares of the 30,205 individual items recorded on this vehicle, and the same share across all cars nationally. A single test can record several items, so a row is not a percentage of tests.
| Category | Items | This car | Nationally | Difference |
|---|---|---|---|---|
| Brakes | 8,539 | 27.70% | 20.89% | +6.81 |
| Tyres | 7,540 | 24.50% | 19.76% | +4.74 |
| Suspension | 6,042 | 19.60% | 20.98% | −1.38 |
| Lamps, reflectors and electrical equipment | 2,776 | 9.00% | 12.21% | −3.21 |
| Non-component advisories | 1,481 | 4.80% | 4.18% | +0.62 |
| Visibility | 1,439 | 4.70% | 4.97% | −0.27 |
| Noise, emissions and leaks | 1,043 | 3.40% | 5.52% | −2.12 |
| Road Wheels | 535 | 1.70% | 0.75% | +0.95 |
| Identification of the vehicle | 409 | 1.30% | 1.76% | −0.46 |
| Body, chassis, structure | 401 | 1.30% | 5.57% | −4.27 |
The exact failure items, in the tester's words
| Recorded item | Severity | Tests | Est. cost |
|---|---|---|---|
| Linkage ball joint dust cover ball joint dust cover severely deteriorated Suspension | Minor | 3.8% | £18–45 |
| Linkage ball joint dust cover ball joint dust cover no longer prevents the ingress of dirt Suspension | Major | 3.3% | £18–45 |
| Coil spring fractured or broken Suspension | Major | 3.2% | £25–65 |
| Windscreen damaged but not adversely affecting driver's view Visibility | Minor | 2.6% | £80–200 |
| Registration plate lamp(s) inoperative in the case of a single lamp or all lamps Lamps, reflectors and electrical equipment | Major | 2.1% | £5–20 |
| Malfunction indicator lamp inoperative or indicates a malfunction Noise, emissions and leaks | Major | 2.0% | £3–12 |
| Ball joint excessively worn Suspension | Major | 1.9% | £18–45 |
| Registration plate lamp(s) inoperative in the case of multiple lamps or light sources Lamps, reflectors and electrical equipment | Minor | 1.8% | £5–20 |
| Ball joint dust cover severely deteriorated Suspension | Minor | 1.8% | £18–45 |
| Rigid brake pipes excessively corroded Brakes | Major | 1.6% | £80–180 |
Severity is as recorded: Major and Dangerous fail the test outright; Minor and Advisory do not. Costs are estimates from typical UK parts prices — see how they are built.
What testers noted without failing the car
Advisories are the early warnings — the same parts a year or two before they fail. Reading them is how you tell a car that has been maintained from one that has been patched.
| Recorded item | Severity | Tests | Est. cost |
|---|---|---|---|
| Tread depth below requirements of 1.6mm Tyres | Advisory | 16.6% | £45–95 |
| Rigid brake pipes excessively corroded Brakes | Advisory | 11.0% | £80–180 |
| Brake discs in such a condition that it is seriously weakened Brakes | Advisory | 8.8% | £45–110 |
| Has a tear, caused by separation or partial failure of its structure Tyres | Advisory | 8.0% | £45–95 |
| Brake pads less than 1.5 mm thick Brakes | Advisory | 7.3% | £18–45 |
| Brake discs significantly and obviously worn Brakes | Advisory | 5.0% | £45–110 |
Pass rate by mileage
| Mileage | Tests | Pass rate | Median odometer |
|---|---|---|---|
| 0-30k | 494 | 90.7% | 23,627 mi |
| 30-60k | 4,423 | 84.8% | 48,253 mi |
| 60-90k | 7,911 | 78.8% | 75,451 mi |
| 90-120k | 5,528 | 77.2% | 103,028 mi |
| 120k+ | 2,820 | 75.9% | 141,203 mi |
Source: 21,184 recorded tests on this vehicle-year. Every row above is recomputed from the same DVSA extract as the rest of the page — see the methodology.
2012 B-Class MOT questions
What is the MOT pass rate for a 2012 Mercedes-Benz B-Class?
79.5% of the 21,184 2012 Mercedes-Benz B-Class tests in this dataset passed, against a national average of 77.2% for cars first used in 2012. First-attempt pass rate: 74.8%.
What are the most common MOT failures on a 2012 Mercedes-Benz B-Class?
The three most recorded items are linkage ball joint dust cover ball joint dust cover severely deteriorated (3.76%), linkage ball joint dust cover ball joint dust cover no longer prevents the ingress of dirt (3.30%), coil spring fractured or broken (3.17%). Percentages are the share of tests on this vehicle that recorded the item.
Does mileage affect the 2012 Mercedes-Benz B-Class MOT pass rate?
Yes. Cars under 30,000 miles passed 90.7% of the time, falling to 75.9% for those over 120,000 miles. The median 2012 Mercedes-Benz B-Class in this dataset had covered 82,028 mi.
Which fuel type is most reliable for a 2012 Mercedes-Benz B-Class?
Diesel: 78.2% pass rate across 15,148 tests. Petrol: 82.8% pass rate across 6,036 tests. Shares are of the tests on this vehicle that recorded each fuel type.
Does the season affect the 2012 Mercedes-Benz B-Class MOT pass rate?
Tests recorded in the winter months (October–March) passed 79.1% of the time; summer months (April–September) passed 80.0%. Brakes, tyres and lights are tested harder in bad weather, but the difference is small on most models.