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Bmw 3 series vs Bmw 840i m sport auto: reliability comparison

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

Bmw 3 series
75%
MOT pass rate · 996,044 vehicles
Bmw 840i m sport auto
88%
MOT pass rate · 3,840 vehicles
More reliable
Verdict: On MOT pass rate, the Bmw 840i m sport auto is the more reliable of the two — 88% pass first time versus 75%. It's one signal among several; check the full breakdown below.

Head to head

Measure Bmw 3 series Bmw 840i m sport auto
MOT pass rate 75% 88% ✓
MOT failure rate 25% 12% ✓
Faults & advisories per test 2.0 0.6 ✓
Dangerous-fault share 2% ✓ 18%
Average mileage 128,558 mi 32,355 mi
Sample size (vehicles) 996,044 3,840

Most common faults

Bmw 3 series

  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. Nearside Front Tyre worn close to the legal limit (4.1.E.1)
  4. Offside Front Tyre worn close to the legal limit (4.1.E.1)
  5. Under-trays fitted obscuring some underside components
  6. Oil leak, but not excessive (8.4.1 (a) (i))

Bmw 840i m sport auto

  1. Nearside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  2. Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  3. Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  4. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  5. Offside Front Tyre has a bulge, caused by separation or partial failure of its structure (5.2.3 (d) (ii))
  6. Offside Front Tyre slightly damaged/cracking or perishing (5.2.3 (d) (ii))

Reliability FAQ

On MOT pass rate, the Bmw 840i m sport auto is the more reliable of the two — 88% pass first time versus 75%. It's one signal among several; check the full breakdown below.

Full Bmw 3 series report Full Bmw 840i m sport auto 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.