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Mercedes-benz C vs Mercedes-benz S320cdi: reliability comparison

MOT pass rates, common faults and mileage compared from real UK MOT data.

Mercedes-benz C
78%
MOT pass rate · 675,043 vehicles
Mercedes-benz S320cdi
67%
MOT pass rate · 2 vehicles
Verdict: On MOT pass rate the Mercedes-benz C (78%) and Mercedes-benz S320cdi (67%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Head to head

Measure Mercedes-benz C Mercedes-benz S320cdi
MOT pass rate 78% ✓ 67%
MOT failure rate 22% ✓ 33%
Faults & advisories per test 1.7 1.7
Dangerous-fault share 3% 0% ✓
Average mileage 112,156 mi 199,998 mi
Sample size (vehicles) 675,043 2

Most common faults

Mercedes-benz C

  1. Nearside Rear Tyre worn close to the legal limit (4.1.E.1)
  2. Offside Rear Tyre worn close to the legal limit (4.1.E.1)
  3. Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  4. Nearside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  5. Under-trays fitted obscuring some underside components
  6. Nearside Front Tyre worn close to the legal limit (4.1.E.1)

Mercedes-benz S320cdi

  1. Front Brake pad(s) less than 1.5 mm thick (3.5.1g)
  2. Front brake disc worn, pitted or scored, but not seriously weakened (3.5.1i)
  3. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  4. Nearside Obligatory mirror damaged, but not seriously affecting the rear view (8.1.2a)
  5. Offside Front Tyre worn close to the legal limit (4.1.E.1)
  6. Offside Rear Tyre worn close to the legal limit (4.1.E.1)

Reliability FAQ

On MOT pass rate the Mercedes-benz C (78%) and Mercedes-benz S320cdi (67%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Full Mercedes-benz C report Full Mercedes-benz S320cdi report Most reliable cars

Pass rates are computed over completed (pass/fail) MOT tests. Reliability also depends on age, mileage and upkeep — see each model's page for the full picture.