Mercedes-Benz SL MOT Failure Rate & Common Faults
We analysed 22,329 MOT tests on the Mercedes-Benz SL carried out in 2023. 17% failed at the first attempt, which is well below the 29% average across all cars in the same data. Put another way, about 8 in 10 SL models passed first time.
Results cover cars first registered from 1983 to 2020. Compared with other cars of the same age, 2005 models did best (83% passed, +26.7 points against the average for 18-year-old cars), while 1984 models fared worst (73%, +0.3 points). Tested cars had covered 66,534 miles on average, against 73,145 across all cars.
The most common reason for failure was lights and electrics, found on 5.0% of tests (noticeably below the 11.3% seen across all cars). The single most frequent fault was "not working", on 2.4% of tests.
- MOT tests analysed
- 22,329
- First-time pass rate
- 83%
- All cars: 71%
- Versus all cars
- +11.5 points
- Average mileage at test
- 66,534
- All cars: 73,145
Checking a particular SL?
See its own MOT history, advisories and mileage for free.
SL MOT pass rate by year
Older cars fail more often, so each year is compared with all cars of the same age. Bars above the dashed line did better than average for their age.
| First registered | Tests | Pass rate | All cars, same age | Difference | Avg mileage |
|---|---|---|---|---|---|
| 2020 | 213 | 93% | 88% | +5.3 points | 12,726 |
| 2019 | 427 | 92% | 86% | +5.6 points | 16,217 |
| 2018 | 417 | 91% | 84% | +6.7 points | 21,912 |
| 2017 | 659 | 90% | 82% | +8.8 points | 26,573 |
| 2016 | 786 | 89% | 79% | +9.9 points | 31,660 |
| 2015 | 816 | 90% | 75% | +14.2 points | 36,805 |
| 2014 | 1,069 | 86% | 72% | +14.7 points | 43,082 |
| 2013 | 1,144 | 84% | 68% | +15.9 points | 45,371 |
| 2012 | 426 | 79% | 66% | +13.5 points | 46,254 |
| 2011 | 262 | 83% | 63% | +19.8 points | 48,780 |
| 2010 | 363 | 80% | 60% | +19.4 points | 56,839 |
| 2009 | 493 | 81% | 59% | +21.5 points | 59,396 |
| 2008 | 783 | 83% | 57% | +25.5 points | 62,805 |
| 2007 | 822 | 82% | 57% | +25.2 points | 69,360 |
| 2006 | 850 | 82% | 56% | +26.0 points | 72,922 |
| 2005 | 1,192 | 83% | 56% | +26.7 points | 73,719 |
| 2004 | 1,961 | 83% | 56% | +26.6 points | 75,222 |
| 2003 | 2,503 | 81% | 57% | +24.6 points | 75,298 |
| 2002 | 1,047 | 81% | 58% | +23.3 points | 75,861 |
| 2001 | 296 | 83% | 59% | +24.1 points | 75,137 |
| 2000 | 507 | 81% | 61% | +20.7 points | 83,361 |
| 1999 | 554 | 81% | 62% | +18.6 points | 82,990 |
| 1998 | 713 | 82% | 64% | +17.9 points | 88,884 |
| 1997 | 702 | 81% | 64% | +16.8 points | 93,160 |
| 1996 | 599 | 80% | 65% | +14.4 points | 94,081 |
| 1995 | 566 | 79% | 66% | +12.3 points | 98,350 |
| 1994 | 409 | 77% | 66% | +10.4 points | 94,922 |
| 1993 | 163 | 75% | 67% | +8.1 points | 89,623 |
| 1992 | 124 | 83% | 68% | +15.0 points | 85,051 |
| 1991 | 124 | 85% | 70% | +15.6 points | 86,679 |
| 1990 | 73 | 85% | 71% | +14.0 points | 80,442 |
| 1989 | 157 | 80% | 72% | +7.9 points | 87,310 |
| 1988 | 138 | 83% | 71% | +12.4 points | 79,726 |
| 1987 | 112 | 78% | 72% | +5.9 points | 82,620 |
| 1986 | 156 | 75% | 71% | +3.6 points | 97,138 |
| 1985 | 192 | 82% | 72% | +10.1 points | 93,580 |
| 1984 | 163 | 73% | 73% | +0.3 points | 95,778 |
| 1983 | 129 | 82% | 75% | +7.2 points | 95,424 |
Why the Mercedes-Benz SL fails its MOT
The share of tests with at least one failure in each area, compared with all cars.
| Failure area | SL | All cars |
|---|---|---|
| Lights and electrics | 5.0% | 11.3% |
| Suspension | 4.7% | 8.9% |
| Tyres | 4.2% | 6.3% |
| Brakes | 3.5% | 6.8% |
| Visibility | 2.3% | 4.8% |
| Noise, emissions and leaks | 1.9% | 3.1% |
| Body and structure | 1.0% | 3.5% |
| Seatbelts and airbags | 0.8% | 1.0% |
| Steering | 0.6% | 1.8% |
| Number plates and VIN | 0.5% | 0.4% |
Top 10 specific failure reasons
- 1not working2.4%
- 2ball joint excessively worn1.3%
- 3fractured or broken1.2%
- 4has ply or cords exposed1.1%
- 5has a cut in excess of the requirements deep enough to reach the ply or cords1.0%
- 6does not clear the windscreen effectively1.0%
- 7ball joint dust cover no longer prevents the ingress of dirt0.9%
- 8too low0.8%
- 9excessively corroded0.8%
- 10has a bulge, caused by separation or partial failure of its structure0.8%
Common SL MOT advisories
Advisories don't cause a fail, but they show what's wearing out. On a used SL, check whether these have been dealt with. Read our guide to MOT advisories.
| Advisory | Area | Share of tests |
|---|---|---|
| tread depth below requirements of 1.6mm | Tyres | 8.6% |
| excessively corroded | Brakes | 8.4% |
| has a tear, caused by separation or partial failure of its structure | Tyres | 6.3% |
| leaking excessively from engine | Noise, emissions and leaks | 4.9% |
| in such a condition that it is seriously weakened | Brakes | 4.9% |
| less than 1.5 mm thick | Brakes | 3.5% |
| ball joint excessively worn | Suspension | 3.4% |
| pin or bush excessively worn | Suspension | 2.7% |
| has excessive play | Suspension | 2.5% |
| excessively deteriorated | Brakes | 1.9% |
Tips to help your SL pass
Based on where SL models most often fail. For a full list, use our pre-MOT checklist.
Lights and electrics · 5.0% of SL tests
Walk round every light
With a helper, check headlights on dipped and main beam, sidelights, brake lights, indicators, the rear fog light and the number plate lamp. Replace blown bulbs in pairs and make sure no lenses are cracked.
Brakes · 3.5% of SL tests
Don't ignore brake warning signs
Grinding, squealing, a soft pedal or the car pulling to one side under braking are all worth investigating before the MOT. Check whether the last test noted worn pads or discs; if so, they may now be below the limit.
Compare with other models
Is the SL ULEZ compliant? See the Mercedes-Benz SL ULEZ check, or view all Mercedes-Benz models.
Other Mercedes-Benz models
Models with similar pass rates
About this data
Based on 22,329 first MOT tests of the Mercedes-Benz SL carried out in 2023.
Source: DVSA anonymised MOT test data (contains public sector information licensed under the Open Government Licence v3.0). First attempts on cars only; “pass rate” means passing first time. Averages cover all 32,735,164 cars tested (71% passed), and years with under 50 tests are hidden.
Learn more about how our data works.
Frequently asked questions
Answers from 22,329 first MOT tests of the Mercedes-Benz SL.
What is the Mercedes-Benz SL MOT failure rate?
In our data, 17% of 22,329 first MOT attempts on the Mercedes-Benz SL ended in a fail, compared with 29% for all cars.
What is the most common reason a Mercedes-Benz SL fails its MOT?
The most common failure areas were lights and electrics (5.0% of tests), suspension (4.7% of tests), tyres (4.2% of tests).
Which SL year has the best MOT pass rate?
Allowing for age, 2005 cars performed best: 83% passed first time, +26.7 points against the average for 18-year-old cars. The weakest was 1984, at 73% (+0.3 points).
How many miles had a typical Mercedes-Benz SL covered at its MOT?
The average was 66,534 miles, against 73,145 for all cars tested. 2020 cars averaged 12,726 miles and 1983 cars 95,424.
What is the most common MOT advisory on the Mercedes-Benz SL?
"tread depth below requirements of 1.6mm" was recorded on 8.6% of tests, in the tyres area. 4.2% of SL models failed in that area too.
How can I check a specific SL's MOT history?
Enter its registration in our free MOT check. Across the 22,329 SL models in our data, first-time pass rates ranged from 73% to 93% by year, so one car's own record says more than the average.
Related guides
- MOT · 6 min readPre-MOT checklist: 20 things to check yourself before the testTwenty quick checks, grouped by area, that you can do on your driveway in under half an hour. No tools beyond a coin and a helper needed for most.Read the guide
- MOT · 6 min readThe most common reasons cars fail their MOT (and how to avoid them)Lights alone failed 11.3% of cars at their 2023 MOT, more than any other area. The common failure areas, ranked, and the driveway checks that prevent them.Read the guide
- MOT · 4 min readTyre tread depth and the MOT: the legal limit and how to check6.3% of cars failed their 2023 MOT on tyres. The 1.6mm legal limit, what testers look for beyond tread, and a one-minute check with a 20p coin.Read the guide
Check any SL's MOT history
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