Mercedes Benz R Class MOT Failures
An analysis of 16,131 real DVSA MOT tests on the Mercedes Benz R Class — what fails, how often, and how that compares to every other car on UK roads.
Where the Mercedes Benz R Class fails its MOT
The single biggest MOT failure point on the Mercedes Benz R Class is parking brake efficiency below minimum requirement — this model is 36 times more likely to fail on this item than the average car on UK roads. That makes it a significant weak point for anyone buying or owning this model. Across 16,131 MOT tests, 1.34% of all Mercedes Benz R Class tests recorded this as a failure.
Brake failures on the MOT range from worn pads and discs (routine maintenance) to corroded brake lines and seized calipers (more serious). Check for any pulling under braking and listen for grinding.
Other notable weak points include transmission shaft constant velocity joint boot... (13x the fleet average), emissions failure (7.9x the fleet average), and anti-roll bar links worn (10x the fleet average). These ratios compare the Mercedes Benz R Class'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 4 categories: Brakes, Bodywork, Exhaust & Emissions, Suspension. If you're inspecting a Mercedes Benz R Class 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 R Class'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.
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 R Class specifically, the DVSA data shows the most common failures at this mileage are parking brake efficiency below minimum requirement (36x the average) and transmission shaft constant velocity joint boot... (13x). anti-roll bar links worn (10x) and anti-roll bar links worn 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 R Class specifically, the DVSA data shows the most common failures at this mileage are parking brake efficiency below minimum requirement (16x the average) and emissions failure (7.9x). transmission shaft constant velocity joint boot... (5.9x) and transmission shaft constant velocity joint boot... also appear frequently.
What to check before buying a Mercedes Benz R Class
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Mercedes Benz R Class:
Brakes — check for parking brake efficiency below minimum requirement. Bodywork — check for transmission shaft constant velocity joint boot.... Exhaust & Emissions — check for emissions failure. Suspension — check for anti-roll bar links worn.
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 R Class?
Enter the reg to see its full MOT history, mileage records, write-off status, and finance checks.
Mercedes Benz R Class MOT FAQs
What are the most common MOT failures on a Mercedes Benz R Class?
Based on 16,131 DVSA MOT tests, the most common failure is parking brake efficiency below minimum requirement — at 36x the national fleet average. Other frequent failures include transmission shaft constant velocity joint boot... and emissions failure.
Is the Mercedes Benz R Class reliable based on MOT data?
The Mercedes Benz R Class has 4 categories where it fails more often than average. The main concern is parking brake efficiency below minimum requirement. Always check a specific car's full history before buying.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Mercedes Benz R Class most commonly fails on parking brake efficiency below minimum requirement and emissions failure. Under 60,000 miles, the main issues are .
How do I check a Mercedes Benz R Class'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.