Model Reports 8 min read Updated 11 Sep 2026 DVSA open data · 2,034 tests analysed

Porsche 911 2018: reliability & common MOT faults

113 first-attempt MOT failures were recorded on the 2018 Porsche 911 in 2025. Figures are among first-attempt failed MOT tests, not among all tests.

First-attempt pass rate 94.4% across 2,034 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

94.4%

of 2,034 first tests (2025)

First tests

2,034

test year 2025

Failed first attempts

113

failed first-attempt tests

MOT pass rates

First-attempt and official-style rates among class 4 first tests of the year.

First-attempt pass

94.4%

of 2,034 first tests (2025)

Official-style pass

95.3%

incl. same-day PRS fixes

First tests

2,034

class 4 · first MOT of the year

Typical age 7.0 yrs · median mileage 19,139 mi

vs 2024: +0.6 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.

Wear patterns

Usage and mileage effects that often track road use rather than model design.

These patterns look like wear or usage effects rather than model-specific design faults. Tyres, brake friction material, and alignment-related defects often track mileage and road use.

Pattern Location Failures vs similar cars Share of fails Confidence
Tyres — Condition (rear)
Tyres > Condition
 Rear 36 ×3.1 31.9% Wear
Note: These patterns are not treated as a model design fault in our common-faults ranking.

Advisories

Notes recorded at the test that appear more often than on similar cars.

Advisory notes recorded on failed first-attempt tests that appear more often than on similar cars.

Advisory pattern Location Notes vs similar cars Share Confidence
Tread depth (rear)
Tyres > Tread depth
 Rear 28 ×5.8 24.8% Wear
Note: Advisories are not a fail rate — they flag issues noted at the test, often before they become failures.

If you are buying one

What this year's MOT record means for the decision in front of you.

Other 911 years worth knowing about

Newer cars always pass more often, so a plain "best year" list would just rank by age. These are the years that beat or miss the trend their own neighbouring years set — the only age-adjusted signal this data supports.

Year vs the years either side First-attempt pass (rises with newer cars) First tests
2021 911 +1.4 pp better 96.9% 1,611
2022 911 -1.5 pp worse 95.4% 2,460

Every figure here is a first-attempt MOT rate from DVSA open data for this model line. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

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, 94.4% of 2,034 first MOTs on the 2018 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 95.3%. Among 113 failed first-attempt MOT tests (test year 2025), we highlight MOT failure patterns that show…
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2018 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.

2024 2025

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.

Contains public sector information licensed under the Open Government Licence v3.0.

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