Mercedes-Benz B-Class: common problems, best years and what to check
Practical premium compact MPV. Covers 2012–2024 cars: every popular engine, its known faults with typical UK repair costs, and how each year has held up on Britain's roads.
Updated November 2026 · By the Carnod team · How we build this guide
Is the Mercedes-Benz B-Class a good used buy?
Best buy
2019+ W247 B200d
Avoid
W246 with harsh DCT
Who it suits: Small families wanting a premium, practical car.
What's good
- Practical
- Premium feel
- Comfortable
- Excellent DfT survival
What's not
- Pricey
- DCT jerkiness
- Dull to drive
- Small market
By the numbers
- #122 most common model on UK roads, with about 65k licensed (DfT).
- The biggest surviving year is 2014: 8.0k cars still licensed.
- 2012 cars survive 8% better than comparable cars of that year.
- The most expensive common fault: Timing chain stretch (up to £2,000).
Mercedes-Benz B-Class common problems by generation and engine
Mercedes-Benz B-Class W246 (2011–2018) · MPV; Electric Drive
How to spot it: 12 plate to 18 plate. Tall hatch with a curved roofline.
B180 / B200 (M270 / M282, petrol, 2012–2018)
Smooth; cold-start rattle on early M270
- Camshaft adjuster rattle at cold start (M270)£600–£1,30040k+
B180d / B200d (OM651, diesel, 2012–2018)
Strong; injectors and chain need watching
- Injector failure / leaks (early Delphi units)£600–£1,80060k+
- Timing chain stretch£1,000–£2,00090k+
Faults on any W246 (2011–2018) engine
- 7G-DCT jerkiness£0–£1,500any
Mercedes-Benz B-Class W247 (2019–) · MPV; 250e
How to spot it: 19 plate onwards. Twin-screen dashboard, A-Class nose.
B180 / B200d / 250e (M282 / OM654q / + e, petrol / diesel / PHEV, 2019–)
Costs are typical UK independent-garage prices including parts and labour. Main dealers usually charge more.
Best and worst Mercedes-Benz B-Class years
How many Mercedes-Benz B-Classs from each year are still licensed today (DfT), coloured by how well that year survives compared with similar cars of the same age.
Years that outlast similar cars: 2012, 2013, 2014, 2015, 2016, 2017, 2018. No year falls off the road noticeably faster than similar cars.
Mercedes-Benz B-Class MOT pass rate and common failures
First-time pass rate (2025)
Average UK car of the same age
MOT tests analysed (2012+ cars)
Mercedes-Benz B-Classs pass their MOT first time 4 points more often than the average UK car of the same age (78% vs 74%). Older cars fail more, so we compare like with like.
| First registered | Pass rate | Average UK car that age | Median mileage |
|---|---|---|---|
| 2012 | 69% | 63% | 86k miles |
| 2013 | 71% | 66% | 80k miles |
| 2014 | 72% | 69% | 75k miles |
| 2015 | 77% | 72% | 66k miles |
| 2016 | 79% | 75% | 57k miles |
| 2017 | 80% | 78% | 51k miles |
| 2018 | 84% | 81% | 40k miles |
| 2019 | 89% | 84% | 33k miles |
| 2020 | 90% | 86% | 29k miles |
| 2021 | 91% | 87% | 25k miles |
| 2022 | 91% | 89% | 20k miles |
Pass rate by fuel
Diesel
Petrol
Fuels differ in age and mileage mix, so treat this as a pattern rather than a like-for-like comparison.
Most common MOT failures
- Coil spring: fractured or broken4.16 per 100
- Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt3.46 per 100
- Drive shafts: constant velocity boot split or insecure, no longer prevents the ingress of dirt2.57 per 100
- Malfunction indicator lamp: inoperative or indicates a malfunction2.52 per 100
- Ball joint excessively worn2.27 per 100
- Registration plate lamp(s): inoperative in the case of a single lamp or all lamps2.26 per 100
- Tyres: has a cut2.12 per 100
- Tread depth below requirements of 1.6mm1.9 per 100
Most common advisories
- Tread depth below requirements of 1.6mm20.39 per 100
- Tyres: has a tear14.48 per 100
- Brake discs: in such a condition that it is seriously weakened11.75 per 100
- Rigid brake pipes: excessively corroded11.25 per 100
- Brake pads: less than 1.5 mm thick9.16 per 100
- Brake discs: significantly and obviously worn5.26 per 100
- Coil spring: corroded4.01 per 100
- Ball joint excessively worn3.5 per 100
Source: DVSA anonymised MOT results for 2025 (normal car tests). First-time pass counts faults fixed during the test as fails. Contains public sector information licensed under the Open Government Licence v3.0.
Does the Mercedes-Benz B-Class have a timing belt or chain?
| Engine | Type | When | Cost |
|---|---|---|---|
| M270/M282 | chain | check from 50k | £600–£1,300 |
| OM651 | chain | check from 80k | £1,000–£2,000 |
Mercedes-Benz B-Class running costs
Road tax (from April 2017)
Road tax (before April 2017)
Insurance groups
Real-world economy
Servicing (independent)
Tyres
Warranty when new
Is the Mercedes-Benz B-Class ULEZ compliant?
- Petrol and hybrid: compliant if Euro 4 — nearly all petrol cars from 2006, many from 2001.
- Diesel: compliant only if Euro 6 — generally cars first registered from September 2015; earlier diesels pay £12.50 a day in London's ULEZ.
- Same standards apply in Birmingham and Bristol Clean Air Zones (which charge private cars) and Scotland's LEZs in Glasgow, Edinburgh, Aberdeen and Dundee (which fine them). Check the exact car on TfL's vehicle checker.
Safety and practicality
Euro NCAP
Boot
Seats
Mercedes-Benz B-Class vs rivals
| Model | On UK roads | Insurance | Boot | Best buy |
|---|---|---|---|---|
| Mercedes-Benz B-Class | 65k | 15–30 | 455 l | 2019+ W247 B200d |
| BMW 2 Series Active Tourer | — | — | — | Guide coming soon |
| VW Golf SV | — | — | — | Guide coming soon |
| Ford C-Max | 99k | 11–22 | 432 l | 2015+ 1.5 TDCi or 1.0 EcoBoost 125 |
| Toyota Verso | — | — | — | Guide coming soon |
| Mercedes-Benz A-Class | 364k | 16–34 | 370 l | 2018+ W177 A180/A200 petrol |
What to check when buying a used Mercedes-Benz B-Class
- DCT software
Mercedes-Benz B-Class FAQ
›Is the Mercedes-Benz B-Class reliable?
Generally, if you pick the right version. Best buy: 2019+ W247 B200d. Avoid: W246 with harsh DCT.
›What is the Mercedes-Benz B-Class MOT pass rate?
78% of Mercedes-Benz B-Classs passed their MOT first time in 2025 (46,358 tests), better than the 74% average for cars of the same age. The most common failure: coil spring: fractured or broken.
›What are the most common Mercedes-Benz B-Class problems?
The costliest known faults are Timing chain stretch; Injector failure / leaks; Camshaft adjuster rattle at cold start. Each one is listed by engine with typical UK repair costs above.
›Does the Mercedes-Benz B-Class have a timing belt or chain?
M270/M282: chain; OM651: chain.
›What is the best year Mercedes-Benz B-Class to buy?
By DfT survival data, 2012, 2013, 2014 cars have outlasted comparable cars best. Condition and history still matter more than the year.
›How much does a Mercedes-Benz B-Class cost to run?
Real-world economy: B180/B200 40–46 mpg; B180d/B200d 52–60 mpg. Insurance groups 15–30. A minor service is about £220–£310 at an independent garage.
›How much is road tax on a Mercedes-Benz B-Class?
Cars registered from April 2017 pay £200 a year (more if the list price was over £40k). Older cars pay by CO2 band, from £20 to £790.
›Is the Mercedes-Benz B-Class ULEZ compliant?
Petrol and hybrid: compliant if Euro 4 — nearly all petrol cars from 2006, many from 2001. Diesel: compliant only if Euro 6 — generally cars first registered from September 2015; earlier diesels pay £12.50 a day in London's ULEZ.
How we build this guide
We combine official UK data with what independent garages see most often on this model.
- How many are still on the road: DfT vehicle licensing statistics, by year first used. The survival comparison is against cars of the same age.
- MOT pass rates, failures and mileage: DVSA anonymised MOT results — every normal car MOT in Great Britain for the year, compared with all cars of the same age.
- Road tax: GOV.UK rates from April 2026. ULEZ: TfL and Clean Air Zone emission standards.
- Faults and repair costs: known problems by engine code, priced at typical UK independent-garage rates including parts and labour.
- Insurance groups, mpg, servicing and tyres: typical ranges, not quotes. Your car's exact figures depend on the version and where you live.
This is a buying guide, not a mechanical inspection. A specific car's MOT history tells you far more than any model average — run a free check on it before you go and see it.
Sources: licensed counts and survival from DfT vehicle licensing statistics; road tax from GOV.UK (April 2026 rates). Faults, costs, mpg and insurance groups are typical ranges, not quotes. A guide, not a mechanical inspection.