Mercedes B
Reliability, estimated running costs, and MOT data across 5 model years from 14,226 MOT tests in 2024.
Avg Pass Rate
95%
Total Tests
14,226
Highest Pass Rate
2021 (95%)
Years Covered
5
About the Mercedes B
The Mercedes B was MOT tested 14,226 times in 2024 (DVSA data, retests included) across 5 model years (2018 to 2022), with an average pass rate of 95%. That's comfortably above the average of 82% across all models in our data. Our records list petrol and diesel versions.
Best and Worst Years
Of the years with at least 100 tests, the 2021 model has the highest pass rate at 95% from 2,521 tests. The 2018 model has the lowest at 91%. With just a 4 point gap, pass rates are similar across these years. Newer cars usually pass more often simply because they are younger.
Reliability Trend
The Mercedes B has maintained consistent MOT pass rates across model years, varying by only 3 percentage points.
Mileage Across Years
The oldest model in our data (2018) averages 36,999 miles, while the newest (2022) averages 23,239 miles.
Compared to the Mercedes brand average of 87%, the B performs 8 points better, making it one of the more reliable options in the Mercedes range.
Estimated Running Costs
Based on 7,400 miles/year, average pump prices of 174.57p petrol and 199.33p diesel (GOV.UK weekly road fuel prices, week of 19 October 2026), and MOT pass rate data. Insurance not included.
Full 2022 detailsHow reliable is the Mercedes B?
Mercedes B by Year
Click any year to see detailed running costs, reliability data, and comparisons with similar cars.
Questions about the Mercedes B
Is the Mercedes B reliable?
Across its 5 model years in our data (2018 to 2022), the Mercedes B averages a 95% MOT pass rate, from 14,226 tests (DVSA MOT data for tests in 2024, retests included). That's 13 points above the average of 82% across all models in the same data. The 2021 model has the highest pass rate of the years with at least 100 tests, at 95%.
Which year Mercedes B has the best MOT pass rate?
Of the years with at least 100 tests, the 2021 Mercedes B has the highest MOT pass rate at 95%, while the 2018 model has the lowest at 91%, a 4 point gap. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.
Are newer Mercedes Bs more reliable?
The Mercedes B has maintained consistent MOT pass rates across model years, varying by only 3 percentage points.
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