Mercedes-Benz B-Class
From 104,041 MOT tests. Average for its class.
Common MOT failure categories
Pass rate by registration year
Newer B-Classs fare better: 2019 models pass at 89.3% vs 65.5% for 2005.
Pass rate by fuel type
What goes wrong?
The most common MOT failure reasons are a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened and a tyre seriously damaged. The top issue, a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, caused 3,051 failures in 2024. Checking tread depth (1.6mm legal minimum, 3mm recommended) before your test can save an unnecessary fail. You can check prices at Black Circles if you need replacements. If you need repairs before retesting, sites like BookMyGarage let you compare local prices.
| a suspension joint dust cover missing or no longer prevents the ingress of dirt etc | 3,051 |
| a spring or spring component fractured or seriously weakened | 2,699 |
| a tyre seriously damaged | 2,643 |
| a suspension pin, bush or joint excessively worn | 2,227 |
| a transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc | 1,868 |
| windscreen washers not working or not providing sufficient fluid to clear the windscreen | 1,524 |
| brake pipe damaged or excessively corroded | 1,464 |
| a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps | 1,398 |
| engine mil illuminated indicating a malfunction | 1,383 |
| a brake lining or pad worn below 1.5mm | 1,382 |
How serious are these failures?
Not all MOT failures are equal. 30.3% of B-Class failures could actually strand you: fractured springs, engine faults, exhaust problems. Another 39.3% are safety issues where the car still drives but shouldn't, such as worn brakes, corroded brake pipes, and steering wear. Breakdown cover may be worth considering for this model. When it does fail, the average repair bill is around £131.
Fuel type matters
Electric versions pass at 86.9% while Petrol versions pass at 75.2%, a 12 percentage point gap.
Mercedes-Benz B-Class on UK roads
The fleet is shrinking: 2,457 scrapped or exported in the past year with only 375 newly registered, a net loss of 2,082. At this rate, roughly 34.2 years until none remain.
Quarterly breakdown
| Quarter | On road | SORN | New | Gone | Net |
|---|---|---|---|---|---|
| 2025 Q3 | 68,214 | 2,921 | +48 | -687 | -639 |
| 2025 Q2 | 68,931 | 2,843 | +93 | -537 | -444 |
| 2025 Q1 | 69,375 | 2,843 | +135 | -660 | -525 |
| 2024 Q4 | 70,075 | 2,668 | +99 | -573 | -474 |
| 2024 Q3 | 70,672 | 2,545 | +170 | -601 | -431 |
| 2024 Q2 | 71,249 | 2,399 | +121 | -554 | -433 |
| 2024 Q1 | 71,715 | 2,366 | +200 | -617 | -417 |
| 2023 Q4 | 72,292 | 2,206 | +323 | -564 | -241 |
20 variants on the road
| Variant | Fuel | Licensed | Share |
|---|---|---|---|
| B200 Blueefficiency Sprt Cdi A | Diesel | 2,404 | 8% |
| B180 Blueefficiency Sprt Cdi A | Diesel | 2,377 | 8% |
| B180 Sport Cdi Auto | Diesel | 2,193 | 7% |
| B180 Cdi Se Cvt | Diesel | 2,086 | 7% |
| B 200 Amg Line Premium + D A | Diesel | 1,919 | 6% |
| B180 Sport Cdi Blue-Cy Auto | Diesel | 1,860 | 6% |
| B180 Sport Cdi Blueefficiency | Diesel | 1,690 | 6% |
| B 200 Sport Executive D Auto | Diesel | 1,660 | 5% |
| B180 Blueefficiency Se Cdi A | Diesel | 1,505 | 5% |
| B180 Blueefficiency Sport Cdi | Diesel | 1,440 | 5% |
| B160 Se Cvt | Petrol | 1,418 | 5% |
| B180 Se Cdi Blueefficiency A | Diesel | 1,289 | 4% |
| B 180 Se D Auto | Diesel | 1,272 | 4% |
| B160 Blueefficiency Sport | Gas | 1,232 | 4% |
| B180 Blueefficiency Se Auto | Petrol | 1,193 | 4% |
| B 200 Amg Line Premium D Auto | Diesel | 1,093 | 4% |
| B200 Cdi Se Cvt | Diesel | 1,074 | 3% |
| B200 Sport Cdi Auto | Diesel | 1,062 | 3% |
| B170 Se Cvt | Petrol | 983 | 3% |
| B180 Blueefficiency Sport | Petrol | 942 | 3% |
Source: DfT vehicle licensing statistics, 2025 Q3. Crown copyright, OGL v3.0.
By registration year
| Year | Pass rate | Top failures |
|---|---|---|
| 2019 | 89.3% | a tyre seriously damaged, a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps |
| 2018 | 88.9% | a tyre seriously damaged, a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps |
| 2017 | 85.9% | a tyre seriously damaged, a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps |
| 2016 | 84.3% | a tyre seriously damaged, a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps |
11 earlier years
| 2015 | 82.6% | a tyre seriously damaged, a rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps |
| 2014 | 80.1% | a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, a tyre seriously damaged |
| 2013 | 78.3% | a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened |
| 2012 | 77.5% | a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened |
| 2011 | 69.4% | a direction indicator lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning, a suspension pin, bush or joint excessively worn |
| 2010 | 68.6% | a suspension pin, bush or joint excessively worn, a suspension joint dust cover missing or no longer prevents the ingress of dirt etc |
| 2009 | 67.6% | a suspension pin, bush or joint excessively worn, a transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc |
| 2008 | 66.6% | a transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, a suspension pin, bush or joint excessively worn |
| 2007 | 66.2% | a transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened |
| 2006 | 66.2% | a transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened |
| 2005 | 65.5% | a transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened |
Typical mileage
Half of all B-Classs tested had between 35,724 and 96,183 miles on the clock.
At 68,819 median miles, the B-Class has 0.034 failures per 10,000 miles driven.
Other Mercedes-Benz models
Common questions
What is the Mercedes-Benz B-Class MOT pass rate?
The Mercedes-Benz B-Class has a 76.9% MOT pass rate based on 104,041 real MOT tests. This is around the national average.
What are common MOT failures on a Mercedes-Benz B-Class?
The most common MOT failure on the Mercedes-Benz B-Class is a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, which caused 3,051 failures. Other common issues include a spring or spring component fractured or seriously weakened.
How many Mercedes-Benz B-Classs are on UK roads?
There are 68,214 Mercedes-Benz B-Classs currently licensed on UK roads, with 2,921 on SORN.
What is the typical mileage of a Mercedes-Benz B-Class at MOT?
The median mileage at MOT for a Mercedes-Benz B-Class is 68,819 miles. The middle 50% of vehicles tested have between 35,724 and 96,183 miles.
Buying a used B-Class?
Start with the free tools. Look up the specific vehicle's MOT history on GOV.UK The mileage at each test will show if it's been wound back, and the advisory history tells you what's wearing. Cross-reference that against the typical failures above to see if anything looks unusual for this model.
The free data won't tell you about outstanding finance, theft markers, or write-off history. For that, you need a vehicle history check This is especially important on a private sale where you have fewer legal protections.
With a 76.9% pass rate and an average repair bill of £131 when things go wrong, budget accordingly. 30.3% of failures on this model could actually strand you, so breakdown cover may be worth considering.
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MOT data from DVSA anonymised test results, 2024 test year. Fleet data from DfT vehicle licensing statistics. Crown copyright, OGL v3.0. MOT pass rates are statistical summaries of test outcomes, not assessments of individual vehicle safety or condition. Always inspect a vehicle and check its full MOT history before purchasing. See terms of use.