MERCEDES B-CLASS (2020)
Running costs, common problems, and reliability data based on 47 real MOT tests in 2024.
MOT Pass Rate
98%
Total Tests (2024)
47
Avg Mileage
23,364 mi
Est. Annual Cost
£1,482
Is the 2020 MERCEDES B-CLASS reliable?
Excellent reliability. Very few MOT failures. That's 16 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.
At 4 years old, 98% of MERCEDES B-CLASSs from 2020 passed their MOT first time in 2024. That's based on 47 tests across the UK. The average mileage at this age is 23,364 miles.
How does the 2020 MERCEDES B-CLASS compare?
Mileage Analysis
The average 2020 MERCEDES B-CLASS has 23,364 miles on the clock, which is below the expected 29,600 miles for a 4-year-old car. This suggests lighter use than average, which generally means less wear on major components.
Best year to buy a MERCEDES B-CLASS?
The most reliable year is the 2019 model with a 93% MOT pass rate, while the 2006 model has the lowest at 71%. The 2020 sits between the two at 98%.
How much does a 2020 MERCEDES B-CLASS cost to run?
Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT pass rate data. Insurance not included.
MERCEDES B-CLASS by Year
| Year | Pass Rate | Tests | Avg Mileage |
|---|---|---|---|
| 2020 | 98% | 47 | 23,364 mi |
| 2019 | 93% | 912 | 29,781 mi |
| 2018 | 90% | 6,729 | 39,021 mi |
| 2017 | 88% | 9,693 | 48,392 mi |
| 2016 | 87% | 9,657 | 55,381 mi |
| 2015 | 86% | 9,871 | 64,066 mi |
| 2014 | 83% | 15,382 | 72,344 mi |
| 2013 | 82% | 13,421 | 78,118 mi |
| 2012 | 81% | 11,092 | 83,827 mi |
| 2011 | 73% | 6,779 | 84,302 mi |
| 2010 | 74% | 8,819 | 90,612 mi |
| 2009 | 74% | 8,277 | 95,335 mi |
| 2008 | 71% | 6,925 | 100,673 mi |
| 2007 | 72% | 5,184 | 101,539 mi |
| 2006 | 71% | 4,235 | 103,535 mi |
| 2005 | 73% | 805 | 105,799 mi |
Checking a specific MERCEDES B-CLASS?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.
About the 2020 MERCEDES B-CLASS
The 2020 MERCEDES B-CLASS is a family car with a 1950cc diesel engine. 47 of these vehicles were MOT tested in 2024, making it a rare model on UK roads. It ranks in the top 7% of all 2020 cars for reliability.
With an average of 23,364 miles at 4 years old, MERCEDES B-CLASS owners tend to use this car less than the typical driver.
2020 MERCEDES B-CLASS Fuel Costs
The 1950cc diesel engine offers a reasonable balance between performance and economy. Expect around 48 mpg in mixed driving, which works out to roughly £1,037 per year at current diesel prices of 148p per litre (based on 7,400 miles per year).
What does it cost to own a 2020 MERCEDES B-CLASS?
Total estimated annual running cost is £1,482 (£124/month), broken down as £1037 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 98% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.
MERCEDES B-CLASS Reliability Trend
Newer MERCEDES B-CLASSs show better MOT pass rates than older ones, with an average improvement of 14 percentage points.
Buying a Used 2020 MERCEDES B-CLASS
At 4 years old, the MERCEDES B-CLASS offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost. If you're flexible on year, the 2019 model has the highest pass rate at 93%. Note: with only 47 tests in our data, these figures should be treated as indicative rather than definitive.
Alternatives to the 2020 MERCEDES B-CLASS
The MERCEDES B-CLASS is actually the most reliable option among similar diesel family cars from this era. Here are comparable diesel cars with similar engines:
- VOLKSWAGEN GOLF (2018) 92% pass rate (-6%) from 111,972 tests
- FORD FOCUS (2019) 89% pass rate (-9%) from 93,803 tests
- MERCEDES A (2019) 91% pass rate (-7%) from 89,588 tests
- MERCEDES A-CLASS (2018) 89% pass rate (-9%) from 81,134 tests