Mercedes Benz Cls MOT Failures
An analysis of 298,498 real DVSA MOT tests on the Mercedes Benz Cls — what fails, how often, and how that compares to every other car on UK roads. Generations covered: C219 (2003–2010), C218 (2011–2018), C257 (2018–2024).
Where the Mercedes Benz Cls fails its MOT
The single biggest MOT failure point on the Mercedes Benz Cls is any fracture or welding defect on a wheel — this model is 506 times more likely to fail on this item than the average car on UK roads. That makes it an extreme outlier for anyone buying or owning this model. Across 298,498 MOT tests, 4.23% of all Mercedes Benz Cls tests recorded this as a failure.
Wheel-related failures include cracked alloys, damaged wheel studs, and bearing play. Listen for rumbling at speed (wheel bearings) and check for any visible cracks around alloy spokes.
Other notable weak points include wheel bearings worn (19x the fleet average), suspension pin, bush or joint worn (13x the fleet average), brake hoses perished or damaged (29x the fleet average), and emissions failure (17x the fleet average). These ratios compare the Mercedes Benz Cls's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 6 categories: Wheels, Suspension, Brakes, Exhaust & Emissions, Bodywork and others. If you're inspecting a Mercedes Benz Cls before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Mercedes Benz Cls's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
For the Mercedes Benz Cls specifically, the DVSA data shows the most common failures at this mileage are any fracture or welding defect on a wheel (319x the average) and brake hoses perished or damaged (29x). emissions failure (17x) and exhaust system damage (16x) also appear frequently.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Mercedes Benz Cls specifically, the DVSA data shows the most common failures at this mileage are parking brake inefficient (64x the average) and any fracture or welding defect on a wheel (12x). window tint too dark (11x) and suspension joint dust cover severely deteriorated (10x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Mercedes Benz Cls specifically, the DVSA data shows the most common failures at this mileage are front or rear fog lamp with a multiple light so... (29x the average) and any fracture or welding defect on a wheel (13x). window tint too dark (11x) and emissions failure (9.9x) also appear frequently.
The shift from any fracture or welding defect on a wheel at lower mileages to front or rear fog lamp with a multiple light so... at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Mercedes Benz Cls specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Brake pipe corrosion and failure Dangerous
CLS models show significantly elevated brake pipe corrosion rates, with MOT data showing failure rates up to 8.1x the fleet average. Affects C219, C218, C257; typical independent garage repair cost is £200–£800.
Wheel bearing excessive play and failure Major
CLS models experience wheel bearing failure at 20.1x the fleet average rate, affecting all engine variants across the model range. Affects C219, C218, C257; typical independent garage repair cost is £300–£500.
Suspension component wear Major
The CLS features a complex multi-link rear suspension with numerous bushes and joints that wear at 16x the fleet average rate. Affects C219, C218, C257; typical independent garage repair cost is £200–£600.
Electronic parking brake failure (C218) Major
Second-generation CLS models with electronic parking brake systems show failure rates 14.4x higher than the fleet average. Affects C218; typical independent garage repair cost is £400–£800.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Mercedes Benz Cls common problems breakdown.
What to check before buying a Mercedes Benz Cls
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Mercedes Benz Cls:
Wheels — check for any fracture or welding defect on a wheel. Suspension — check for wheel bearings worn, suspension pin, bush or joint worn. Brakes — check for brake hoses perished or damaged, parking brake inefficient.
Beyond the MOT items, ask specifically about brake pipe corrosion and failure and wheel bearing excessive play and failure. These won't show up on a standard MOT but can be expensive to fix — repairs start from £200. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Mercedes Benz Cls?
Enter the reg to see its full MOT history, mileage records, write-off status, and finance checks.
Mercedes Benz Cls MOT FAQs
What are the most common MOT failures on a Mercedes Benz Cls?
Based on 298,498 DVSA MOT tests, the most common failure is any fracture or welding defect on a wheel — at 506x the national fleet average. Other frequent failures include wheel bearings worn and suspension pin, bush or joint worn.
Is the Mercedes Benz Cls reliable based on MOT data?
The Mercedes Benz Cls has 15 MOT failure categories above the fleet average. Specialists also flag brake pipe corrosion and failure as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Mercedes Benz Cls most commonly fails on front or rear fog lamp with a multiple light so... and any fracture or welding defect on a wheel. Under 60,000 miles, the main issues are any fracture or welding defect on a wheel and brake hoses perished or damaged.
How do I check a Mercedes Benz Cls's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.