Mercedes-Benz SLK years to avoid — 153,005 MOT tests ranked

No clear negative outlier after correcting for age. Strongest in the data: 2002. The ranking uses 153,005 MOT tests across 16 registration years (2023–2025) and compares each year with all UK cars of the same age. Fuel-type signal: diesels show an average 5.9-point pass-rate deficit on this model. That may reflect mileage and use as well as the car itself, so inspect DPF and emissions history rather than treating fuel type as a verdict.

Every SLK year, ranked

The age-adjusted MOT index sets 100 as the pass rate of all UK cars registered in the same year and tested in the same calendar year. Higher is better. This prevents an old car being labelled a “bad year” simply because it is old.

RankYearIndexVs same-agePass rateTests
1 2002 Strong 111.9 +11.9 pts 77.7% 5,528
2 2001 110.1 +10.1 pts 76.8% 6,218
3 2011 109.4 +9.4 pts 78.6% 7,403
4 2003 108.5 +8.5 pts 73.6% 5,058
5 2006 107.2 +7.2 pts 71.6% 10,788
6 2005 106.7 +6.7 pts 71.2% 13,925
7 2008 106.3 +6.3 pts 71.4% 9,411
8 2010 106.2 +6.2 pts 73.6% 6,106
9 2012 106.1 +6.1 pts 77.3% 16,341
10 2007 106.1 +6.1 pts 71.2% 10,293
11 2009 105.8 +5.8 pts 72.2% 7,333
12 2004 105.7 +5.7 pts 70.1% 8,890
13 2014 104.8 +4.8 pts 80.7% 14,281
14 2015 104.5 +4.5 pts 83.2% 14,302
15 2013 104.3 +4.3 pts 77.6% 13,440
16 2016 104.1 +4.1 pts 85.4% 3,688

How to use this before buying

  • Rankings describe the cohort, not the car. A cherished older example beats a neglected 2002 one — always run the specific reg through the free MOT history check.
  • Read the advisories. Repeated notes for the same component across years mean the owner has been ignoring it. Decode them in our advisory library.
  • Fuel matters on this model. The diesel deficit (5.9 points) usually traces to DPF and emissions kit on low-mileage use — check for P2463-type soot codes on the test drive.
  • Scan before you pay. A 2-minute OBD scan reveals stored faults the dashboard hides — see our scanner guide.

FAQs

Which SLK years should I avoid?

No year is a clear negative outlier after correcting for age, so buy on condition and history rather than year.

What is the best SLK year to buy used?

2002 lead the age-adjusted MOT ranking. The score compares each registration year with all UK cars of the same age; the specific car's history and condition still take priority.

Is the SLK reliable overall?

Across 153,005 tests, the median age-adjusted index is 106.2 (100 equals the pass rate of all cars registered in the same year). Use the spread between years as one signal, then check the individual registration.

Methodology: index = 100 + the model-year cohort’s MOT pass-rate difference versus all UK vehicles registered in the same year and tested in the same calendar year. Class 4 initial tests only; retests excluded; at least 1,500 tests per page. “Inspect” years are below both the same-age baseline and the model’s median index by at least 2 points. Association is not proof of a model-year defect. DVSA anonymised data 2023–2025, OGL v3.0.