What are the main MOT differences between BMW 3 Series and Mercedes-Benz C-Class?

The BMW 3 Series has a 26.1% overall MOT failure rate (1,841,976 tests) while the Mercedes-Benz C-Class has 23.4% (1,739,497 tests). The top failure area for the BMW 3 Series is lamps & electrics, while for the Mercedes-Benz C-Class it is suspension.

Should I buy a BMW 3 Series or Mercedes-Benz C-Class?

From an MOT reliability standpoint, the Mercedes-Benz C-Class has a lower failure rate. However, MOT pass rates are just one factor — also consider insurance costs, fuel economy, running costs and personal preference. Use AutoSafe's free prediction tool to check a specific vehicle by registration.

BMW 3 Series vs Mercedes-Benz C-Class — MOT Failure Rate Comparison

Q: Which is more reliable, BMW 3 Series or Mercedes-Benz C-Class?

Based on 3,581,473 MOT tests, the Mercedes-Benz C-Class is more reliable with a 2.7 percentage point lower failure rate. The BMW 3 Series has a 26.1% failure rate while the Mercedes-Benz C-Class has 23.4%.

BMW 3 Series

26.1%

failure rate from 1,841,976 tests

2.0pp below UK avg (28%)

Mercedes-Benz C-Class

23.4%

failure rate from 1,739,497 tests

4.6pp below UK avg (28%)

Verdict: The Mercedes-Benz C-Class is more reliable based on MOT data, with a 2.7 percentage point lower failure rate than the BMW 3 Series.

Failure Rate by Vehicle Age

How the BMW 3 Series and Mercedes-Benz C-Class compare across different age groups:

Age	BMW 3 Series	Mercedes-Benz C-Class	Difference
0-2 years	12.7%	10.3%	Mercedes-Benz C-Class +2.3pp
3-5 years	11.5%	12.3%	BMW 3 Series +0.8pp
6-10 years	20.4%	20.1%	Mercedes-Benz C-Class +0.3pp
11-15 years	30.2%	33.0%	BMW 3 Series +2.8pp
15+ years	33.3%	39.5%	BMW 3 Series +6.1pp

Component Risk Comparison

Side-by-side breakdown of which MOT failure areas each model is weaker in:

BMW 3 Series Component Mercedes-Benz C-Class

5.2%

Lamps & Electrics

3.2%

3.9%

Suspension

4.6%

3.7%

Brakes

3.1%

3.7%

Tyres

3.6%

2.0%

Visibility

1.3%

0.8%

Body & Chassis

0.5%

0.4%

Steering

0.4%

Component	BMW 3 Series	Mercedes-Benz C-Class	Better
Lamps & Electrics	5.2%	3.2%	Mercedes-Benz C-Class
Suspension	3.9%	4.6%	BMW 3 Series
Brakes	3.7%	3.1%	Mercedes-Benz C-Class
Tyres	3.7%	3.6%	Mercedes-Benz C-Class
Visibility	2.0%	1.3%	Mercedes-Benz C-Class
Body & Chassis	0.8%	0.5%	Mercedes-Benz C-Class
Steering	0.4%	0.4%	BMW 3 Series

Which Is More Reliable: BMW 3 Series or Mercedes-Benz C-Class?

Based on official DVSA MOT test records covering 3,581,473 tests between these two models, the Mercedes-Benz C-Class comes out ahead with a 2.7 percentage point lower overall failure rate. The Mercedes-Benz C-Class fails 23.4% of the time compared to the BMW 3 Series's 26.1%.

However, the gap between these models varies by vehicle age. Younger examples of both models tend to have more similar pass rates, while differences can become more pronounced as vehicles age and accumulate wear. Component-level data shows each model has different weak spots — the BMW 3 Series's top risk area is lamps & electrics while the Mercedes-Benz C-Class's is suspension. Knowing your model's specific weaknesses helps you target pre-MOT checks where they matter most.

Explore Each Model in Detail

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Data methodology: Failure rates are weighted averages across all mileage bands, calculated from official DVSA MOT test records. Only age/mileage combinations with 100+ tests are included. Component risks represent the probability of failure in each specific area. Data covers 142 million MOT tests across the UK. Comparisons are based on aggregate statistics and individual vehicle condition will vary.

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