Mercedes Benz B Class (2009)
2009 Mercedes Benz B Class
CarHunch analysed 5,689 real MOT records for the 2009 Mercedes Benz B Class.
Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
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The 2009 Mercedes-Benz B-Class falls slightly below the UK average with a 77.8% first-time pass rate, but the real concern is that 45.2% of these vehicles have recorded a dangerous defect at some point—well above the typical threshold and a serious red flag for buyers. Petrol and diesel variants perform nearly identically (78.1% and 77.5% respectively), so fuel type won't meaningfully change your odds here.
At nearly 71,000 miles median mileage for a 15-year-old car, these B-Classes have been driven fairly hard, and the data reflects it: owners face an average of 3.85 failures and 22.4 advisories per test cycle. Before committing to one, get a thorough pre-purchase inspection focusing on suspension, braking system, and electrical components—the high dangerous defect rate suggests structural or safety-critical wear is common in this generation.
The 2009 Mercedes Benz B Class has a decent first-time pass rate (77.8%), but a higher-than-average share of vehicles have had serious defects recorded — the individual vehicle's history matters a lot here.
These stats describe 5,689 vehicles as a group. The specific vehicle you're looking at could be the one good example or the one outlier. Run its registration to find out.
What tends to go wrong
Across 5,689 vehicles — figures show how many had each issue flagged at least once in their MOT history.
Data covers a 3-year window centred on 2009.
See this vehicle's full MOT history & AI hunches
Spot recurring advisories, hidden issues, and how it compares to 5,689 Mercedes Benz B Class cars.
Before you buy a 2009 Mercedes Benz B Class
Based on MOT data from 5,689 vehicles — here's what to check.
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Check the full MOT history.
45.2% of these vehicles have had a dangerous defect recorded -
recurring advisories often signal problems years before they become failures.
Search the reg on CarHunch for the full MOT history, reliability stats and a free AI-powered analysis of that exact vehicle. -
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Brake pipes, sills and subframes are the key areas on a vehicle this age — structural rust is hard to spot without getting underneath. A mechanic will check all of this before you commit, and give you a concrete basis to negotiate on price.
Inspection
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Outstanding finance, insurance write-offs and clocking won't appear in the MOT records — a dedicated history check covers all of this. Our link gets you 20% off automatically.
History
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Pass Rate by Fuel Type
| Fuel type | Vehicles | Pass rate | Avg failures |
|---|---|---|---|
| Diesel (53%) | 2,995 | 77.5% | 3.88 |
| Petrol (47%) | 2,694 | 78.1% | 3.83 |
Colour Breakdown
Based on 77,010 Mercedes Benz B Class vehicles registered in the UK — across all years. From DVLA registration records.
Mileage Distribution
Most 2009 Mercedes Benz B Class vehicles sit in the blue band. If the vehicle you're looking at is outside it, it's either unusually low or high mileage for its age.
Half of all 2009 Mercedes Benz B Class vehicles fall between 55,994 and 86,141 miles.
2009 Mercedes Benz B Class — Still on the Road
Most 2009 Mercedes Benz B Classs are still being driven.
3,801 vehicles still getting MOTs in 2025 — 70% of the peak remain.
Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2014–2025.
* The 2020 dip reflects the government's COVID-19 MOT exemption, which allowed certificates to be extended by six months — fewer tests were conducted that year.
MOT History Averages
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Compare with another model
See how the 2009 Mercedes Benz B Class stacks up against a rival.