Skip to content

Porsche 911 carrera 4s auto vs Porsche Boxster: reliability comparison

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

Porsche 911 carrera 4s auto
94%
MOT pass rate · 116 vehicles
More reliable
Porsche Boxster
83%
MOT pass rate · 46,488 vehicles
Verdict: On MOT pass rate, the Porsche 911 carrera 4s auto is the more reliable of the two — 94% pass first time versus 83%. It's one signal among several; check the full breakdown below.

Head to head

Measure Porsche 911 carrera 4s auto Porsche Boxster
MOT pass rate 94% ✓ 83%
MOT failure rate 6% ✓ 17%
Faults & advisories per test 0.4 ✓ 1.4
Dangerous-fault share 11% 1% ✓
Average mileage 19,003 mi 74,547 mi
Sample size (vehicles) 116 46,488

Most common faults

Porsche 911 carrera 4s auto

  1. Offside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  2. Nearside Front Tyre slightly damaged/cracking or perishing (5.2.3 (d) (ii))
  3. Offside Front Tyre slightly damaged/cracking or perishing (5.2.3 (d) (ii))
  4. Nearside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  5. Offside Front Tyre worn close to legal limit/worn on edge (5.2.3 (e))
  6. Nearside Rear Tyre worn close to legal limit/worn on edge (5.2.3 (e))

Porsche Boxster

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

Reliability FAQ

On MOT pass rate, the Porsche 911 carrera 4s auto is the more reliable of the two — 94% pass first time versus 83%. It's one signal among several; check the full breakdown below.

Full Porsche 911 carrera 4s auto report Full Porsche Boxster 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.