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Mercedes-benz 300 s vs Mercedes-benz C: reliability comparison

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

Mercedes-benz 300 s
90%
MOT pass rate · 5 vehicles
Mercedes-benz C
78%
MOT pass rate · 675,043 vehicles
Verdict: On MOT pass rate the Mercedes-benz 300 s (90%) and Mercedes-benz C (78%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Head to head

Measure Mercedes-benz 300 s Mercedes-benz C
MOT pass rate 90% ✓ 78%
MOT failure rate 10% ✓ 22%
Faults & advisories per test 1.0 ✓ 1.7
Dangerous-fault share 10% 3% ✓
Average mileage 102,880 mi 112,156 mi
Sample size (vehicles) 5 675,043

Most common faults

Mercedes-benz 300 s

  1. Exhaust emits blue smoke during acceleration (8.2.1.2 (g))
  2. under trays and engine covers fitted obscuring view of certain testable components
  3. All tyres starting to perish
  4. Hazard warning switch faulty (4.4.2 (a) (i))
  5. Suspension system inoperative (5.3.5 (a))
  6. Front Tyre slightly damaged/cracking or perishing BOTH (5.2.3 (d) (ii))

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)

Reliability FAQ

On MOT pass rate the Mercedes-benz 300 s (90%) and Mercedes-benz C (78%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Full Mercedes-benz 300 s report Full Mercedes-benz C 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.