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Porsche 911 speedster vs Porsche Boxster: reliability comparison

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

Porsche 911 speedster
95%
MOT pass rate · 153 vehicles
More reliable
Porsche Boxster
83%
MOT pass rate · 46,488 vehicles
Verdict: On MOT pass rate, the Porsche 911 speedster is the more reliable of the two — 95% pass first time versus 83%. It's one signal among several; check the full breakdown below.

Head to head

Measure Porsche 911 speedster Porsche Boxster
MOT pass rate 95% ✓ 83%
MOT failure rate 5% ✓ 17%
Faults & advisories per test 0.2 ✓ 1.4
Dangerous-fault share 0% ✓ 1%
Average mileage 11,748 mi 74,547 mi
Sample size (vehicles) 153 46,488

Most common faults

Porsche 911 speedster

  1. Nearside rear brake binding (3.7.B.1)
  2. Nearside Front Wheel bearing has slight play (5.1.3 (a) (i))
  3. Offside Rear Tyre has a cut but not deep enough to reach the ply or cords (5.2.3 (d) (i))
  4. Undertrays and covers fitted, blocking the visual inspection of various components
  5. Windscreen washer provides insufficient washer liquid (8.2.3)
  6. Nearside Front Lower Anti-roll bar linkage rubber mounting deteriorated but not resulting in excessive movement (2.4.G.2)

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 speedster is the more reliable of the two — 95% pass first time versus 83%. It's one signal among several; check the full breakdown below.

Full Porsche 911 speedster 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.