2018 Mercedes-Benz S-Class MOT pass rate: 92.0% (6,906 tests)
Is the 2018 S-Class getting worse?
Pass rate of 2018-registered cars across recent test years:
| Test year | Pass rate | |
|---|---|---|
| 2023 | 92.6% +4.6 vs same-age |
|
| 2024 | 91.2% +5.0 vs same-age |
|
| 2025 | 92.1% +7.4 vs same-age |
The raw rate normally falls as cars age. The “vs same-age” figure compares this cohort with all UK cars registered in the same year, so normal ageing is not mistaken for a bad model year.
What fails on a 2018 S-Class
| # | System | Defects recorded | Share |
|---|---|---|---|
| 1 | Tyres | 415 | 45.7% |
| 2 | Suspension | 131 | 14.4% |
| 3 | Brakes | 82 | 9.0% |
| 4 | Noise, emissions and leaks | 63 | 6.9% |
| 5 | Visibility | 57 | 6.3% |
| 6 | Road Wheels | 51 | 5.6% |
All S-Class years compared
| Registration year | Tests | Pass rate | Vs same-age | Median mileage |
|---|---|---|---|---|
| 2003 | 1,900 | 78.7% | +13.7 pts | 115,919 |
| 2004 | 1,841 | 80.6% | +16.3 pts | 118,826 |
| 2005 | 1,552 | 76.7% | +12.2 pts | 119,516 |
| 2006 | 3,053 | 81.3% | +16.8 pts | 106,916 |
| 2007 | 3,770 | 78.5% | +13.4 pts | 112,922 |
| 2008 | 2,835 | 78.3% | +13.1 pts | 110,325 |
| 2009 | 2,506 | 77.6% | +11.2 pts | 107,166 |
| 2010 | 2,525 | 81.4% | +14.0 pts | 104,488 |
| 2011 | 2,738 | 82.2% | +13.0 pts | 103,872 |
| 2012 | 3,602 | 81.9% | +10.7 pts | 95,720 |
| 2013 | 2,919 | 83.9% | +10.5 pts | 98,348 |
| 2014 | 4,826 | 89.2% | +13.3 pts | 83,909 |
| 2015 | 6,465 | 88.6% | +9.9 pts | 75,164 |
| 2016 | 8,005 | 88.4% | +7.1 pts | 62,049 |
| 2017 | 7,087 | 89.0% | +4.9 pts | 59,650 |
| 2018 (this page) | 6,906 | 92.0% | +5.6 pts | 60,718 |
| 2019 | 6,929 | 92.8% | +4.4 pts | 57,335 |
Weighing up which year to buy? See the full ranking: Mercedes-Benz S-Class years to avoid.
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FAQs
Is a 2018 Mercedes-Benz S-Class reliable?
2018-registered examples passed 92.0% of their MOT tests (6,906 tests, 2023–2025), +5.6 points versus all UK cars registered in the same year. At roughly 8 years old with a median 60,718 miles, condition now varies car by car — always check the individual MOT history.
What mileage is too high for a 2018 S-Class?
The median tested example shows 60,718 miles. Anything far beyond that isn't automatically bad — a motorway-mile car with consistent service records often beats a low-mileage school-run car — but price accordingly and scrutinise the mileage trail for gaps or drops.
Source: DVSA Anonymised MOT tests and results, 2023–2025 extracts (96 million Class 4 initial tests; retests excluded). Only vehicles old enough for a routine first MOT are included. Age-adjusted figures compare the model-year cohort with all vehicles of the same registration year tested in the same calendar year. Contains public sector information licensed under OGL v3.0.