Mercedes Benz
53,078 MOT tests analysed. sits above the UK fleet average — here's where SLs pass, fail, and end up on the retest sheet.
That's 8.6 points above the UK fleet average across our 1,984 tracked models — a confident result.
Pass
86.1%
Pass-after-fix
2.6%
Fail
10.6%
Avg miles
68,693
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 .
Performance by cohort
2 year bands · 53,073 tests
Pass rate climbs 8.9 points across the cohorts — newer SL examples clear the test more reliably than the early cars.
Pass
85.9%
Fail
10.8%
PRS
2.6%
Avg mileage at test
69,956 mi
Pass
94.7%
Fail
4.1%
PRS
0.8%
Avg mileage at test
22,651 mi
Cohort = vehicle's first-registration year band. Same model, different generations of build.
Generations on file · 5
Mercedes Benz SL · UK market
1972–1989
1989–2001
2001–2012
2012–2021
2021–now
Photos: Wikimedia Commons · CC BY-SA / CC BY / public domain.
The picture
The Mercedes Benz SL 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 24,773 tests puts this car on a 83.9% first-time pass rate, above the UK fleet average. Average mileage at test is 68,247 miles. The most common fail item is suspension joint dust cover severely deteriorated, followed by cracked or discoloured windscreen.
The new Mercedes SL is a different animal to its predecessor, with a more aggressive exterior, a larger cabin offering 2+2 accommodation (in theory) and a fabric soft-top. Long-haul ability is sublime, but it’s not as sporting as you’d hope.
For used buyers, the SL's pass rate suggests it clears the MOT with fewer surprises than most — but the top failure items above are still worth a pre-purchase inspection, particularly on higher-mileage examples.
ABI Insurance Group
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 →
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A suspension joint dust cover severely deteriorated
1,192 occurrences · 2.2% of tests
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
705 occurrences · 1.3% of tests
A suspension joint dust cover missing or no longer prevents the ingress of dirt etc
444 occurrences · 0.8% of tests
A tyre cords visible or damaged
426 occurrences · 0.8% of tests
Brake pipe damaged or excessively corroded
412 occurrences · 0.8% of tests
A tyre seriously damaged
395 occurrences · 0.7% of tests
A spring or spring component fractured or seriously weakened
371 occurrences · 0.7% of tests
A rear registration plate lamp or light source missing or inoperative in the case of multiple lamps or light sources
351 occurrences · 0.7% of tests
A suspension pin, bush or joint excessively worn
335 occurrences · 0.6% of tests
A tyre seriously damaged
269 occurrences · 0.5% 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
£260–£665
If every one of this SL'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 →
Try the calculator
Build your own retest budget.
Year-band analysis
First-time MOT pass rate split by registration band. A 8.9-point gap between bands means the year you buy Mercedes Benz SL has a real effect on what turns up at the garage.
Best band to buy
94.7%
2018–2020 registration
the 2018–2020 band climbs to 94.7% — a 8.9-point improvement. Tests in this band average 22,651 miles — roughly 47K miles fewer on the clock than the older band. Failures here are mostly wear items: has a cut in excess of the…, damaged but not adversely affecting driver's view — the structural issues that drag down older examples don't appear in the top-10 for this band. The stricter post-2018 MOT test rules meant manufacturers had to tighten up emissions and electrical checks, but this band still shows far fewer major failures on suspension and bodywork than the older fleet.
Band to be cautious about
85.9%
Pre-2018 registration
On the older band (pre-2018), the data shows a 85.9% pass rate against a fleet average of 94.7% on the newer band. The main culprits logged at test: ball joint dust cover severely deteriorated, damaged but not adversely affecting driver's view, and ball joint dust cover no longer prevents…. Average mileage on test for this band is 69,956 miles — high-mileage wear items are a recurring theme.
Best band to buy: 2018-2020 (94.7% first-time pass). Worst band to avoid: pre-2018 (85.9% pass). That's a 8.9-point spread across 51,668 older tests and 1,405 newer ones — year of build makes a material difference on this model.
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Owner reports · Honest John
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
£110,000 for a 2.0-litre AMG is undeniably pricey.
Recall history
The SL has 13 official UK vehicle recalls covering defect details, remedies, and affected build dates.
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 an SL 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.
