Mercedes-Benz Slk
From 117,017 MOT tests. Above average for its class.
Common MOT failure categories
Pass rate by registration year
Newer Slks fare better: 2016 models pass at 86.8% vs 75.2% for 1997.
Pass rate by fuel type
What goes wrong?
The most common MOT failure reasons are a spring or spring component fractured or seriously weakened, a suspension pin, bush or joint excessively worn and a tyre seriously damaged. The top issue, a spring or spring component fractured or seriously weakened, caused 3,895 failures in 2024. Checking tread depth (1.6mm legal minimum, 3mm recommended) before your test can save an unnecessary fail. You can check prices at Black Circles if you need replacements. If you need repairs before retesting, sites like BookMyGarage let you compare local prices.
| a spring or spring component fractured or seriously weakened | 3,895 |
| a suspension pin, bush or joint excessively worn | 3,536 |
| a tyre seriously damaged | 1,908 |
| tyre tread depth not in accordance with the requirements | 1,908 |
| a suspension joint dust cover missing or no longer prevents the ingress of dirt etc | 1,737 |
| brake pipe damaged or excessively corroded | 1,639 |
| the aim of a headlamp is not within limits laid down in the requirements | 1,447 |
| a tyre cords visible or damaged | 1,387 |
| windscreen washers not working or not providing sufficient fluid to clear the windscreen | 1,008 |
| a suspension component excessively damaged or corroded | 881 |
How serious are these failures?
Not all MOT failures are equal. 20.1% of Slk failures could actually strand you: fractured springs, engine faults, exhaust problems. Another 43.8% are safety issues where the car still drives but shouldn't, such as worn brakes, corroded brake pipes, and steering wear. When it does fail, the average repair bill is around £132.
Fuel type matters
Diesel versions pass at 83.7% while Petrol versions pass at 78%, a 6 percentage point gap.
Mercedes-Benz Slk on UK roads
The fleet is shrinking: 1,747 scrapped or exported in the past year with only 9 newly registered, a net loss of 1,738. At this rate, roughly 34 years until none remain. Now at 82.5% of its peak (71,530 in 2016 Q2).
Quarterly breakdown
| Quarter | On road | SORN | New | Gone | Net |
|---|---|---|---|---|---|
| 2025 Q3 | 48,982 | 10,061 | +6 | -539 | -533 |
| 2025 Q2 | 49,928 | 9,648 | +0 | -178 | -178 |
| 2025 Q1 | 47,854 | 11,900 | +0 | -334 | -334 |
| 2024 Q4 | 48,181 | 11,907 | +3 | -696 | -693 |
| 2024 Q3 | 51,274 | 9,507 | +2 | -280 | -278 |
| 2024 Q2 | 52,064 | 8,995 | +2 | -0 | +542 |
| 2024 Q1 | 50,551 | 9,966 | +2 | -1,520 | -1,518 |
| 2023 Q4 | 50,901 | 11,134 | +6 | -589 | -583 |
20 variants on the road
| Variant | Fuel | Licensed | Share |
|---|---|---|---|
| Slk 200 Kompressor Auto | Petrol | 10,126 | 23% |
| Slk250 Amg Sport Cdi Blue-Cy A | Diesel | 8,732 | 20% |
| Slk 230 Kompressor Auto | Gas | 4,188 | 9% |
| Slk200 Amg Sport Blue-Ciency A | Petrol | 3,411 | 8% |
| Slk 200 Kompressor | Petrol | 3,065 | 7% |
| Slk 350 Auto | Petrol | 2,739 | 6% |
| Slk280 Auto | Petrol | 2,094 | 5% |
| Slk 250 D Amg Sport Auto | Diesel | 1,786 | 4% |
| Slk250 Cdi Blueefficiency Auto | Diesel | 1,671 | 4% |
| Slk 320 Auto | Petrol | 962 | 2% |
| Slk200 Amg Sport Ed125 Bl-Cy A | Petrol | 835 | 2% |
| Slk200 Blueefficiency Auto | Petrol | 768 | 2% |
| Slk 230 Kompressor | Petrol | 637 | 1% |
| Slk 280 Auto | Petrol | 564 | 1% |
| Slk200 Amg Sport Blue-Ciency | Petrol | 556 | 1% |
| Slk 200 Amg Sport Auto | Petrol | 539 | 1% |
| Slk 55 Amg Auto | Petrol | 522 | 1% |
| Slk350 Amg Sport Blue-Ciency A | Petrol | 519 | 1% |
| Slk200 Kompressor Auto | Petrol | 429 | <1% |
| Slk250 Amg Sport Blue-Ciency A | Petrol | 428 | <1% |
Source: DfT vehicle licensing statistics, 2025 Q3. Crown copyright, OGL v3.0.
By registration year
| Year | Pass rate | Top failures |
|---|---|---|
| 2016 | 86.8% | a tyre seriously damaged, a spring or spring component fractured or seriously weakened |
| 2015 | 86% | a spring or spring component fractured or seriously weakened, a tyre seriously damaged |
| 2014 | 85.2% | a spring or spring component fractured or seriously weakened, a suspension joint dust cover missing or no longer prevents the ingress of dirt etc |
| 2013 | 83.5% | a spring or spring component fractured or seriously weakened, a suspension joint dust cover missing or no longer prevents the ingress of dirt etc |
16 earlier years
| 2012 | 82.7% | a suspension joint dust cover missing or no longer prevents the ingress of dirt etc, a spring or spring component fractured or seriously weakened |
| 2011 | 84.1% | a spring or spring component fractured or seriously weakened, a suspension joint dust cover missing or no longer prevents the ingress of dirt etc |
| 2010 | 78% | a spring or spring component fractured or seriously weakened, a suspension pin, bush or joint excessively worn |
| 2009 | 77.5% | a spring or spring component fractured or seriously weakened, a suspension pin, bush or joint excessively worn |
| 2008 | 78.1% | a spring or spring component fractured or seriously weakened, a suspension pin, bush or joint excessively worn |
| 2007 | 76.3% | a suspension pin, bush or joint excessively worn, a spring or spring component fractured or seriously weakened |
| 2006 | 75.9% | a suspension pin, bush or joint excessively worn, a spring or spring component fractured or seriously weakened |
| 2005 | 75.6% | a suspension pin, bush or joint excessively worn, a spring or spring component fractured or seriously weakened |
| 2004 | 74% | a suspension pin, bush or joint excessively worn, a spring or spring component fractured or seriously weakened |
| 2003 | 72.8% | the aim of a headlamp is not within limits laid down in the requirements, a spring or spring component fractured or seriously weakened |
| 2002 | 75.5% | the aim of a headlamp is not within limits laid down in the requirements, brake pipe damaged or excessively corroded |
| 2001 | 73.9% | the aim of a headlamp is not within limits laid down in the requirements, stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning |
| 2000 | 74.7% | the aim of a headlamp is not within limits laid down in the requirements, windscreen washers not working or not providing sufficient fluid to clear the windscreen |
| 1999 | 73.7% | the aim of a headlamp is not within limits laid down in the requirements, windscreen washers not working or not providing sufficient fluid to clear the windscreen |
| 1998 | 74.6% | the aim of a headlamp is not within limits laid down in the requirements, stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning |
| 1997 | 75.2% | the aim of a headlamp is not within limits laid down in the requirements, stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning |
Typical mileage
Half of all Slks tested had between 69,243 and 110,539 miles on the clock. A significant number are high-mileage vehicles.
At 95,737 median miles, the Slk has 0.021 failures per 10,000 miles driven.
Other Mercedes-Benz models
Common questions
What is the Mercedes-Benz Slk MOT pass rate?
The Mercedes-Benz Slk has a 79.5% MOT pass rate based on 117,017 real MOT tests. This is above the national average.
What are common MOT failures on a Mercedes-Benz Slk?
The most common MOT failure on the Mercedes-Benz Slk is a spring or spring component fractured or seriously weakened, which caused 3,895 failures. Other common issues include a suspension pin, bush or joint excessively worn.
How many Mercedes-Benz Slks are on UK roads?
There are 48,982 Mercedes-Benz Slks currently licensed on UK roads, with 10,061 on SORN.
What is the typical mileage of a Mercedes-Benz Slk at MOT?
The median mileage at MOT for a Mercedes-Benz Slk is 95,737 miles. The middle 50% of vehicles tested have between 69,243 and 110,539 miles.
Buying a used Slk?
Start with the free tools. Look up the specific vehicle's MOT history on GOV.UK The mileage at each test will show if it's been wound back, and the advisory history tells you what's wearing. Cross-reference that against the typical failures above to see if anything looks unusual for this model.
The free data won't tell you about outstanding finance, theft markers, or write-off history. For that, you need a vehicle history check This is especially important on a private sale where you have fewer legal protections.
With a 79.5% pass rate and an average repair bill of £132 when things go wrong, budget accordingly.
Some links are to services we may earn from. Disclosure.
MOT data from DVSA anonymised test results, 2024 test year. Fleet data from DfT vehicle licensing statistics. Crown copyright, OGL v3.0. MOT pass rates are statistical summaries of test outcomes, not assessments of individual vehicle safety or condition. Always inspect a vehicle and check its full MOT history before purchasing. See terms of use.