Comparison · executive cars

Mercedes-Benz C-Class vs Audi A4: which is more reliable?

The Mercedes-Benz C-Class and Audi A4 are very close at the MOT: scores of 106 and 106. Pick on the condition and history of the actual car. Based on 611,485 real MOT tests in 2024.

By age

MOT Rank score for each age group (100 = an average car that age).

Age at test	Mercedes-Benz C-Class	Audi A4
3–5 years	102About average	102About average
6–9 years	105Above average	102Above average
10–14 years	107Above average	110Well above average
15+ years	106Above average	109Well above average

Year by year

Share that passed first time, same registration year.

Year	Mercedes-Benz C-Class	Audi A4
2021	86.8%	87.7%
2020	87.7%	88.6%
2019	87.0%	86.5%
2018	84.8%	83.5%
2017	82.5%	81.1%
2016	80.8%	78.5%
2015	78.7%	75.7%
2014	76.4%	73.9%
2013	69.9%	72.9%
2012	67.8%	71.3%
2011	67.7%	69.4%
2010	65.8%	67.7%
2009	63.6%	65.7%
2008	62.7%	63.1%
2007	61.1%	62.5%
2006	58.6%	61.4%
2005	57.9%	61.0%
2004	57.0%	59.0%
2003	57.5%	58.3%
2002	60.9%	58.4%
2001	61.5%	59.8%
2000	67.3%	63.0%
1999	71.1%	66.2%
1998	70.7%	69.0%
1997	70.4%	62.1%
1996	73.2%	69.2%

Problem areas

Failure items per 100 tests.

Area	Mercedes-Benz C-Class	Audi A4
Suspension	13.0	11.3
Lights & electrics	8.2	11.5
Tyres	8.8	8.8
Brakes	9.3	7.6
Emissions & leaks	4.2	3.9
Visibility (wipers, screen, mirrors)	2.8	3.4
Body & chassis	1.2	4.6
Steering	0.8	1.5

Mercedes-Benz C-Class: top failures

Suspension arms - ball joint: ball joint excessively worn4.2%
Tread depth below requirements of 1.6mm3.1%
Coil spring: fractured or broken2.6%
Malfunction indicator lamp: inoperative or indicates a malfunction2.3%
Tyres - condition: has ply or cords exposed1.6%
Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt1.3%

Audi A4: top failures

Coil spring: fractured or broken3.4%
Tread depth below requirements of 1.6mm3.2%
Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt2.8%
Suspension arms - pins and bushes: pin or bush excessively worn1.9%
Malfunction indicator lamp: inoperative or indicates a malfunction1.6%
Tyres - condition: has ply or cords exposed1.4%

Questions

Which is more reliable, the Mercedes-Benz C-Class or the Audi A4?

The Mercedes-Benz C-Class and Audi A4 are very close at the MOT: scores of 106 and 106. Pick on the condition and history of the actual car.

Which years of the Mercedes-Benz C-Class and Audi A4 can be compared?

Both were tested for 26 registration years (1996–2021). The Mercedes-Benz C-Class had the higher pass rate in 13 of them and the Audi A4 in 13.

What fails most on each?

Mercedes-Benz C-Class: suspension arms - ball joint: ball joint excessively worn; tread depth below requirements of 1.6mm. Audi A4: coil spring: fractured or broken; tread depth below requirements of 1.6mm.