Mercedes B-Class

Reliability, estimated running costs, and MOT data across 16 model years from 117,828 MOT tests in 2024.

Avg Pass Rate

81%

Total Tests

117,828

Highest Pass Rate

2019 (93%)

Years Covered

About the Mercedes B-Class

The Mercedes B-Class was MOT tested 117,828 times in 2024 (DVSA data, retests included) across 16 model years (2005 to 2020), with an average pass rate of 81%. That's close to the average of 82% across all models in our data. Our records list diesel and electric and petrol versions.

Best and Worst Years

Of the years with at least 100 tests, the 2019 model has the highest pass rate at 93% from 912 tests. The 2006 model has the lowest at 71%. With a 22 point gap, the year you choose makes a real difference. Newer cars usually pass more often simply because they are younger.

Reliability Trend

Newer Mercedes B-Classs pass their MOT more often than older ones, by 14 percentage points on average, which is mostly down to age and wear.

Mileage Across Years

The oldest model in our data (2005) averages 105,799 miles, while the newest (2020) averages 23,364 miles. Older models have covered serious mileage, so suspension and drivetrain wear are worth checking.

Compared to the Mercedes brand average of 87%, the B-Class is 6 points lower, placing it among the less reliable Mercedes models.

Estimated Running Costs

Fuel (Diesel, 1950cc)

£1,397

Road Tax

£200

MOT Test

£55

Predicted Repairs

£200

Total per year£1,852

Per month£154/mo

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 2020 details

How reliable is the Mercedes B-Class?

vs average of all models-1% (82% avg)

vs Mercedes brand average-6% (87% avg)

Best to worst year spread22 percentage points

Reliability trendImproving over years

Mercedes B-Class by Year

Click any year to see detailed running costs, reliability data, and comparisons with similar cars.

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

Questions about the Mercedes B-Class

Is the Mercedes B-Class reliable?

Across its 16 model years in our data (2005 to 2020), the Mercedes B-Class averages an 81% MOT pass rate, from 117,828 tests (DVSA MOT data for tests in 2024, retests included). That's 1 point below the average of 82% across all models in the same data. The 2019 model has the highest pass rate of the years with at least 100 tests, at 93%.

Which year Mercedes B-Class has the best MOT pass rate?

Of the years with at least 100 tests, the 2019 Mercedes B-Class has the highest MOT pass rate at 93%, while the 2006 model has the lowest at 71%, a 22 point gap. Newer cars usually pass more often simply because they are younger, so compare years of a similar age.