EngineHigh
N20/N26 timing chain and guide wear (earlier builds most affected).
Mercedes-Benz C-Class vs BMW 3 Series · reliability compared
Both scores come from the documented faults we hold for each model · severity weighted, then priced at UK independent-garage rates so you can see which car carries the bigger risk.
The short answer
On the faults we hold, the Mercedes-Benz C-Class scores 8.1 against 6.7 for the BMW 3 Series · fewer or less severe documented problems. The BMW 3 Series carries the higher worst-case repair bill.
Mercedes-Benz C-Class
2015–2021
8.1/ 10
Strong- Documented faults
- 4
- Critical / high
- 0 / 0
- Medium / low
- 3 / 1
- Priciest job
- £120–£1,200
- Worst-case total
- £3,800
Weak spots · Electrical, Body, Engine, Suspension
BMW 3 Series
2012–2018
6.7/ 10
Solid- Documented faults
- 4
- Critical / high
- 0 / 2
- Medium / low
- 2 / 0
- Priciest job
- £900–£2,600
- Worst-case total
- £6,400
Weak spots · Engine, Cooling
The faults that decide it
CoolingHigh
Electric water pump and thermostat failure.
Scores are computed from the documented faults in our library for each model · they reflect reported patterns, not the condition of a specific car.
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