Model Reports 8 min read Updated 11 Sep 2026 DVSA open data · 725 tests analysed

Mercedes-Benz Sl 2008: reliability & common MOT faults

116 first-attempt MOT failures were recorded on the 2008 Mercedes-Benz Sl in 2025. Figures are among first-attempt failed MOT tests, not among all tests.

First-attempt pass rate 84.0% across 725 tests in 2025. On 725 tests that is too small a sample to separate this year from the Sls either side of it — treat the recorded failures as a checklist, not as a verdict on the year.

First-attempt pass

84.0%

of 725 first tests (2025)

First tests

725

test year 2025

Failed first attempts

116

failed first-attempt tests

MOT pass rates

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

First-attempt pass

84.0%

of 725 first tests (2025)

Official-style pass

85.4%

incl. same-day PRS fixes

First tests

725

class 4 · first MOT of the year

Typical age 17.0 yrs · median mileage 63,881 mi

vs 2024: +2.2 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.

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 (front)
Tyres > Condition
 Front 20 ×2.8 17.2% Wear
Note: These patterns are not treated as a model design fault in our common-faults ranking.

If you are buying one

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

There are too few 2008 Sls in the data to call this year good or bad. Judge the individual car, not the year.

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.

On 725 tests that is too small a sample to separate this year from the Sls either side of it — treat the recorded failures as a checklist, not as a verdict on the year. In 2025, 84.0% of 725 first MOTs on the 2008 Mercedes-Benz Sl passed first time (PRS — items fixed at the station the same day — counted as a fail). The official-style rate including PRS is 85.4%. Among 116 failed first-attempt MOT tests (test year 2…
This page highlights MOT failure patterns for the 2008 Mercedes-Benz Sl (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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