Mercedes Benz
Slk
128,932 MOT tests analysed. lands in the middle of the pack — here's where Slks pass, fail, and end up on the retest sheet.
That's 1.5 points above the UK fleet average across our 1,984 tracked models — a confident result.
Pass
79.0%
Pass-after-fix
3.1%
Fail
17.3%
Avg miles
71,448
Pass + Pass-after-fix + Fail = 100%
This model's production run straddles the January 2006 Euro 4 cutoff. Individual cars vary — check your registration plate on the government's ULEZ checker. Daily charges if driven in the zone: London £12.50 · Birmingham £8.00 .
Generations on file · 3
Mercedes Benz Slk · UK market
1996–2004
2004–2011
2011–2020
Photos: Wikimedia Commons · CC BY-SA / CC BY / public domain.
The picture
Mercedes Benz SLK: mixed MOT record across 71,871 tests
The Mercedes Benz SLK is a petrol-powered car sold in the UK market across multiple generations, covering a broad date range in the test population.
MOT data from 71,871 tests puts this car on a 76.7% first-time pass rate, roughly in line with the UK fleet average. Average mileage at test is 69,863 miles. The most common fail item is fractured or weakened suspension spring, followed by tyre tread below the legal limit.
Buyers weighing up a used SLK should treat the failure breakdown as a pre-purchase checklist. The pass rate is reasonable, but the gap between first attempt and a clean sheet narrows with age and mileage.
ABI Insurance Group
Group 30–44
A high-group car — insurance costs will be significantly above average. Lower groups cost less to insure; UK fleet average is around Group 22.
Source: ABI Group Rating Panel · administered by Thatcham Research · groups cover standard variants; performance trims may sit higher. Browse all insurance groups →
30–44
out of 50
Top ten reasons for rejection.
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- 01
A spring or spring component fractured or seriously weakened
4,110 occurrences · 3.2% of tests
- 02
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
2,347 occurrences · 1.8% of tests
- 03
A suspension pin, bush or joint excessively worn
2,303 occurrences · 1.8% of tests
- 04
Headlamp reflector or lens slightly defective
2,059 occurrences · 1.6% of tests
- 05
Tyre tread depth not in accordance with the requirements
1,975 occurrences · 1.5% of tests
- 06
Brake pipe damaged or excessively corroded
1,773 occurrences · 1.4% of tests
- 07
A tyre cords visible or damaged
1,463 occurrences · 1.1% of tests
- 08
A suspension joint dust cover severely deteriorated
1,427 occurrences · 1.1% of tests
- 09
A suspension pin, bush or joint excessively worn
1,027 occurrences · 0.8% of tests
- 10
A suspension joint dust cover severely deteriorated
1,013 occurrences · 0.8% of tests
Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.
Worst-case fix budget · top 4 failures
£230–£655
If every one of this Slk's most-logged Major fails hit at the same MOT, that's the real-world UK garage range. Reality is usually one or two items, not all of them. Open the estimator →
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Build your own retest budget.
Tools that pre-empt a retest.
Picked against this car's top failure patterns. Affiliate links to Amazon UK — we earn a small cut at no cost to you. Disclosed up-front, doesn't shape the data.
Item 01 · Amazon UK
Headlight restoration kit
Yellowed lenses fail the light-output test. A restoration kit lifts the haze in an afternoon for £20.
Search Amazon UK
Item 02 · Amazon UK
Digital tyre-tread depth gauge
Five quid for a gauge beats £150 for a retest. UK MOT minimum is 1.6mm — most testers fail anything below 2mm to be safe.
Search Amazon UK
My Motor World · affiliate
Parts & supplies for this fix
Affiliate links — small commission, no extra cost to you.
Click Mechanic · affiliate
Book a mobile mechanic
Affiliate links — small commission, no extra cost to you.
Mobile mechanic · UK-wide
Book a mechanic at your door.
Fixed-price quotes upfront. No garage needed. Click Mechanic sends a vetted local mechanic to you — home, work, or roadside.
Owner reports · Honest John
What owners actually report.
Verbatim faults logged by owners on honestjohn.co.uk over recent years. We didn't summarise — these are the words people typed in.
Where it falls short
Owner reports (11 entries) flag recurring problems with paint/body, electrical faults, water/oil leaks.
Recall history
5 UK recalls on record.
The Slk has 5 official UK vehicle recalls covering defect details, remedies, and affected build dates.
Buying or keeping a Slk?
Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.
If you own a Slk and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.