Mercedes-Benz Cls MOT Failure Rate & Common Faults
We analysed 25,217 MOT tests on the Mercedes-Benz Cls carried out in 2023. 25% failed at the first attempt, which is slightly below the 29% average across all cars in the same data. Put another way, about 8 in 10 Clses passed first time.
Results cover cars first registered from 2005 to 2020. Compared with other cars of the same age, 2005 models did best (72% passed, +15.5 points against the average for 18-year-old cars), while 2020 models fared worst (78%, −10.1 points). Tested cars had covered 86,894 miles on average, against 73,145 across all cars.
The most common reason for failure was tyres, found on 9.9% of tests (slightly above the 6.3% seen across all cars). The single most frequent fault was "has ply or cords exposed", on 3.2% of tests.
- MOT tests analysed
- 25,217
- First-time pass rate
- 75%
- All cars: 71%
- Versus all cars
- +3.7 points
- Average mileage at test
- 86,894
- All cars: 73,145
Checking a particular Cls?
See its own MOT history, advisories and mileage for free.
Cls 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 | 285 | 78% | 88% | −10.1 points | 25,572 |
| 2019 | 1,117 | 83% | 86% | −3.6 points | 34,098 |
| 2018 | 1,001 | 83% | 84% | −1.3 points | 42,246 |
| 2017 | 1,526 | 83% | 82% | +1.0 points | 52,035 |
| 2016 | 2,155 | 81% | 79% | +2.7 points | 62,356 |
| 2015 | 2,956 | 82% | 75% | +6.9 points | 73,973 |
| 2014 | 1,867 | 76% | 72% | +4.7 points | 80,452 |
| 2013 | 3,190 | 75% | 68% | +6.8 points | 90,825 |
| 2012 | 1,177 | 75% | 66% | +9.5 points | 92,583 |
| 2011 | 1,273 | 76% | 63% | +13.2 points | 98,245 |
| 2010 | 1,168 | 65% | 60% | +4.9 points | 108,302 |
| 2009 | 1,218 | 65% | 59% | +5.8 points | 111,238 |
| 2008 | 1,542 | 68% | 57% | +10.3 points | 118,745 |
| 2007 | 1,976 | 67% | 57% | +10.2 points | 120,777 |
| 2006 | 1,699 | 69% | 56% | +12.7 points | 118,604 |
| 2005 | 1,053 | 72% | 56% | +15.5 points | 105,705 |
Why the Mercedes-Benz Cls fails its MOT
The share of tests with at least one failure in each area, compared with all cars.
| Failure area | Cls | All cars |
|---|---|---|
| Tyres | 9.9% | 6.3% |
| Suspension | 7.7% | 8.9% |
| Brakes | 6.3% | 6.8% |
| Lights and electrics | 5.2% | 11.3% |
| Noise, emissions and leaks | 2.9% | 3.1% |
| Visibility | 2.0% | 4.8% |
| Road Wheels | 1.5% | 0.4% |
| Steering | 1.2% | 1.8% |
| Body and structure | 1.0% | 3.5% |
| Number plates and VIN | 0.5% | 0.4% |
Top 10 specific failure reasons
- 1has ply or cords exposed3.2%
- 2fractured or broken3.1%
- 3tread depth below requirements of 1.6mm2.6%
- 4ball joint excessively worn2.6%
- 5excessively corroded2.4%
- 6inoperative or indicates a malfunction2.0%
- 7has a cut in excess of the requirements deep enough to reach the ply or cords2.0%
- 8not working1.8%
- 9ball joint dust cover no longer prevents the ingress of dirt1.6%
- 10has a bulge, caused by separation or partial failure of its structure1.5%
Common Cls MOT advisories
Advisories don't cause a fail, but they show what's wearing out. On a used Cls, 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 | 17.0% |
| excessively corroded | Brakes | 12.4% |
| less than 1.5 mm thick | Brakes | 7.5% |
| in such a condition that it is seriously weakened | Brakes | 7.2% |
| leaking excessively from engine | Noise, emissions and leaks | 4.7% |
| has excessive play | Suspension | 4.4% |
| ball joint excessively worn | Suspension | 4.0% |
| has a tear, caused by separation or partial failure of its structure | Tyres | 4.0% |
| pin or bush excessively worn | Suspension | 3.0% |
| significantly and obviously worn | Brakes | 2.9% |
Tips to help your Cls pass
Based on where Clses most often fail. For a full list, use our pre-MOT checklist.
Brakes · 6.3% of Cls 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.
Lights and electrics · 5.2% of Cls 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.
Compare with other models
Is the Cls ULEZ compliant? See the Mercedes-Benz Cls ULEZ check, or view all Mercedes-Benz models.
Other Mercedes-Benz models
Models with similar pass rates
About this data
Based on 25,217 first MOT tests of the Mercedes-Benz Cls 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 25,217 first MOT tests of the Mercedes-Benz Cls.
What is the Mercedes-Benz Cls MOT failure rate?
In our data, 25% of 25,217 first MOT attempts on the Mercedes-Benz Cls ended in a fail, compared with 29% for all cars.
What is the most common reason a Mercedes-Benz Cls fails its MOT?
The most common failure areas were tyres (9.9% of tests), suspension (7.7% of tests), brakes (6.3% of tests).
Which Cls year has the best MOT pass rate?
Allowing for age, 2005 cars performed best: 72% passed first time, +15.5 points against the average for 18-year-old cars. The weakest was 2020, at 78% (−10.1 points).
How many miles had a typical Mercedes-Benz Cls covered at its MOT?
The average was 86,894 miles, against 73,145 for all cars tested. 2020 cars averaged 25,572 miles and 2005 cars 105,705.
What is the most common MOT advisory on the Mercedes-Benz Cls?
"tread depth below requirements of 1.6mm" was recorded on 17.0% of tests, in the tyres area. 9.9% of Clses failed in that area too.
How can I check a specific Cls's MOT history?
Enter its registration in our free MOT check. Across the 25,217 Clses in our data, first-time pass rates ranged from 65% to 83% by year, so one car's own record says more than the average.
Related guides
- 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
- 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 · 6 min readDangerous, major and minor MOT defects explainedSince 2018, every fault found at an MOT goes into one of four categories. Knowing the difference tells you whether you can drive home, and what to fix first.Read the guide
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