Model Reports
8 min readUpdated 11 Sep 2026
DVSA open data · 1,247 tests analysed
Porsche 911 2011: reliability & common MOT faults
106 first-attempt MOT failures were recorded on the 2011 Porsche 911 in 2025. Figures are among first-attempt failed MOT tests, not among all tests.
First-attempt pass rate 91.5% across 1,247 tests in 2025. Nothing in this year's figures separates it from the 911 either side — no fuel gap, and no break in the model's own trend.
First-attempt pass
91.5%
of 1,247 first tests (2025)
First tests
1,247
test year 2025
Failed first attempts
106
failed first-attempt tests
MOT pass rates
First-attempt and official-style rates among class 4 first tests of the year.
First-attempt pass
91.5%
of 1,247 first tests (2025)
Official-style pass
92.2%
incl. same-day PRS fixes
First tests
1,247
class 4 · first MOT of the year
Typical age 14.0 yrs · median mileage 44,350 mi
vs 2024:
-0.2 pp first-attempt
Note:
Class 4 cars · first MOT of the year per vehicle · P/PRS/F outcomes (2025 data).
PRS (fixed at the station the same day) counts as a fail in the first-attempt rate.
Raw outcomes for this cohort — not adjusted for age, mileage, or peer mix.
MOT doesn't test engine or gearbox internals.
Common faults
Failure patterns that show up more often on this registration year than on similar cars.
These MOT failure patterns show up more often on this registration year than on
similar cars of the same class, age, and mileage.
Shares below are measured across the 106 failed
first attempts in 2025
that the age-and-mileage comparison can be computed on.
Standout: Drive shafts — Joints (front) — 19.8% of this year's failed first attempts
Recorded on 21 of those tests. It tops the table on elevation — about 5.7× more often than on similar cars of the same age and mileage. The full ranked list is in the table below.
No patterns met the strongest callout thresholds on this page; showing the highest-lift
rows that still cleared the display floors.
Only patterns that clear minimum sample and elevation thresholds are shown
(at least 20 failures and about
2.0× more often than similar cars).
Note: Rates and comparisons are among first-attempt failed tests, not all MOTs. Patterns come from MOT defect codes — not manufacturer service bulletins, recalls, or a diagnosis of any individual car. Failures and advisories are listed separately.
FAQs
Short answers about how to read this model-year guide.
Nothing in this year's figures separates it from the 911 either side — no fuel gap, and no break in the model's own trend. In 2025, 91.5% of 1,247 first MOTs on the 2011 Porsche 911 passed first time (PRS — items fixed at the station the same day — counted as a fail). The official-style rate including PRS is 92.2%. Among 106 failed first-attempt MOT tests (test year 2025), Drive shafts — Joints (front) appears more…
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Drive shafts — Joints (front) (19.8% of those tests; 21 observed failures; about 5.7× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Drive shafts — Joints (front) shows up more often than on similar cars (19.8% of those tests; 21 observed failures; about 5.7× more often than similar cars). That does not prove a design fault — age, mileage, and how the car was used still matter. Treat it as a pre-purchase check point, not a manufacturer service bulletin.
Common MOT problem areas for the 2011 Porsche 911 include Drive shafts — Joints (front). These patterns show up more often than on similar cars after we filter out sparse noise — not a full list of every possible fault on an individual car.
This page highlights MOT failure patterns for the 2011 Porsche 911 (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics — not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.
About this data
How this page is built and what it can (and can't) say.
These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars — not a full reliability score, and not a pass/fail verdict on any individual vehicle.
20242025
What we include
UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.
Same-day repairs
PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.
How we compare
We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.
What this does not cover
MOTs do not cover engine internals, gearboxes, or many electronics — this is not a full reliability score.
Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
Age and mileage matching reduces — but does not remove — differences in how cars were used and maintained.
We never invent pass rates, star scores, or ranks when those data marts are missing.