2004 Mercedes-Benz SL MOT pass rate: 85.1% (5,427 tests)
Is the 2004 SL getting worse?
Pass rate of 2004-registered cars across recent test years:
| Test year | Pass rate | |
|---|---|---|
| 2023 | 84.8% +20.9 vs same-age |
|
| 2024 | 85.2% +21.2 vs same-age |
|
| 2025 | 85.4% +20.2 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 2004 SL
| # | System | Defects recorded | Share |
|---|---|---|---|
| 1 | Suspension | 530 | 29.5% |
| 2 | Brakes | 403 | 22.5% |
| 3 | Tyres | 280 | 15.6% |
| 4 | Lamps, reflectors and electrical equipment | 236 | 13.1% |
| 5 | Visibility | 92 | 5.1% |
| 6 | Noise, emissions and leaks | 61 | 3.4% |
All SL years compared
| Registration year | Tests | Pass rate | Vs same-age | Median mileage |
|---|---|---|---|---|
| 2002 | 2,872 | 83.7% | +18.0 pts | 73,879 |
| 2003 | 6,974 | 83.5% | +18.4 pts | 74,302 |
| 2004 (this page) | 5,427 | 85.1% | +20.8 pts | 73,646 |
| 2005 | 3,317 | 84.4% | +19.9 pts | 72,624 |
| 2006 | 2,379 | 83.4% | +18.9 pts | 72,034 |
| 2007 | 2,326 | 83.4% | +18.2 pts | 67,976 |
| 2008 | 2,255 | 85.1% | +20.0 pts | 62,436 |
| 2013 | 3,359 | 84.3% | +11.0 pts | 45,701 |
| 2014 | 3,147 | 87.4% | +11.6 pts | 43,438 |
| 2015 | 2,372 | 88.6% | +9.9 pts | 37,269 |
| 2016 | 2,291 | 90.6% | +9.2 pts | 32,791 |
| 2017 | 1,901 | 91.6% | +7.6 pts | 27,262 |
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FAQs
Is a 2004 Mercedes-Benz SL reliable?
2004-registered examples passed 85.1% of their MOT tests (5,427 tests, 2023–2025), +20.8 points versus all UK cars registered in the same year. At roughly 22 years old with a median 73,646 miles, condition now varies car by car — always check the individual MOT history.
What mileage is too high for a 2004 SL?
The median tested example shows 73,646 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.