Mercedes-Benz CLS C257 (2018-2024) reliability
Mercedes-Benz CLS C257 built around 2018: more dangerous faults than average
Testers find a dangerous fault on Mercedes-Benz CLS C257 models built around 2018 more often than on similar cars the same age. Look closely at the tyres on any car you view.
Looking at a Mercedes-Benz CLS C257?
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Key figure
6% of MOT tests on Mercedes-Benz CLS C257 models built around 2018 found a fault the tester marked as dangerous, against 4% for similar cars the same age.
Most common issue
The most common MOT issue on Mercedes-Benz CLS C257 models built around 2018 involves the tyres.
Based on 2,613 tests of CLS models registered 2018-2024.
About 1 in 30 CLS C257 MOTs (3.4%) failed and still hadn't passed 3 days later. That's for cars built around 2018 (7 years old), all fuels combined.
Based on 612 tests (DVSA MOT results, 2025), a small sample, so the figure is likely between 2.3% and 5.2%. A fail that passed a retest within 3 days, even the same day, isn't counted. Nor is a fail with no later MOT on record.
About 1 in 15 CLS C257 MOTs (5.9%) found at least one dangerous defect. These are cars built around 2018 (7 years old).
Based on 612 tests (DVSA MOT results, 2025), a small sample, so the figure is likely between 4.3% and 8.0%. Dangerous is the most serious grade an MOT gives: a direct risk to road safety.
C257 fail rate by age
Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs. Highest fail rate at 4 years old.
How the CLS C257 compares
At each age below, see how the CLS C257 holds up against other cars the same age. The averages combine all fuel types.
Based on 182,274 tests across 17 Mercedes-Benz models, built around 2018 (7 years old).
Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs.
What to check before viewing
The model's most common MOT issues, turned into things you can ask about or look for.
Independent inspection
High priorityHave an independent specialist inspect the car before you commit.
Brake discs
High priorityAsk for the date and mileage of the last disc replacement; visually check for a deep wear lip and rust pitting on each disc.
Brake pads
High priorityAsk when the pads were last replaced and check the warning-light history.
Tyres
Worth checkingCheck tread depth across the full width on all four; uneven wear suggests alignment or suspension issues.
Vehicle-specific check
Worth checkingCheck the car’s number plate on MOT Wise to see its own MOT history and any recalls for its build years.
Other saloons to compare
Other saloons, with each one's figures taken at the same age as the CLS C257.
- 1
Lexus IS
Same body type, tested at the same age
- Fail rate
- 9%
- Fail, no pass in 3 days
- 1.4%
- Dangerous
- 3.8%
- Still registered at 10 years
- 79.4%
Lower fail rate: 9.0%, against 13.6% for the Mercedes-Benz CLS C257, both built around 2018.
2 critical recall campaigns matching this model/build period.
1,615 MOT tests on cars built around 2018
- 2
BMW 7 Series
Same body type, tested at the same age
- Fail rate
- 8.9%
- Fail, no pass in 3 days
- 2.5%
- Dangerous
- 3.9%
- Still registered at 10 years
- 79.9%
Lower fail rate: 8.9%, against 13.6% for the Mercedes-Benz CLS C257, both built around 2018.
6 critical recall campaigns matching this model/build period.
1,659 MOT tests on cars built around 2018
- 3
BMW M3
Same body type, tested at the same age
- Fail rate
- 9.8%
- Fail, no pass in 3 days
- 3.2%
- Dangerous
- 3.9%
Lower fail rate: 9.8%, against 13.6% for the Mercedes-Benz CLS C257, both built around 2018.
10 critical recall campaigns matching this model/build period.
1,139 MOT tests on cars built around 2018
- 4
Porsche Panamera
Same body type, tested at the same age
- Fail rate
- 9.2%
- Fail, no pass in 3 days
- 4%
- Dangerous
- 5.5%
- Still registered at 10 years
- 86.2%
Lower fail rate: 9.2%, against 13.6% for the Mercedes-Benz CLS C257, both built around 2018.
2 critical recall campaigns matching this model/build period.
1,105 MOT tests on cars built around 2018
- Fail rate
- = the share of MOT tests that ended in a fail. Retests count as tests.
- Fail, no pass in 3 days
- = the share of MOT tests that failed and still hadn't passed 3 days later. A fail that passed a retest within 3 days, even the same day, isn't counted.
- Dangerous
- = the share of MOT tests where the tester marked a fault as dangerous. It is against the law to drive the car until it is fixed.
- Still registered at 10 years
- = the share of cars still registered (taxed or declared off the road) 10 years after they were first registered.
Recall context
53 recalls in all24 of the 53 CLS C257 recalls cover cars built in these years.
- 24 recalls
Top concerns
- SRPC2603 - drive shaft joint
- SRPC2409 - tightness of transmission wiring harness connector
- SRPC2412 - tightness of transmission wiring harness connector
For the exact car, check GOV.UK's recall checker with the number plate.
What has gone wrong on CLS C257 cars built around 2018
The share of diesel cars that have ever failed an MOT on each part of the car. Based on 69 cars.
How CLS C257 cars have aged
How CLS C257 cars have aged
How fail rates have changed as these cars got older. Each line follows cars first registered in about the same year across several years of MOT data. Not a prediction for any one car.
How each part holds up as C257 cars age
How each part holds up as C257 cars age
The share of diesel cars built 2017-2020 that have ever failed an MOT on each part of the car. Rates usually rise with age, but can dip slightly as cars leave the road.
| Part of the car | 6 years | 7 years | 8 years |
|---|---|---|---|
| Suspension | 12% | 9% | 11% |
| Brakes | 1% | 3% | 12% |
| Emissions | No figure | 6% | 5% |
| Tyres | 28% | 32% | 35% |
| Lighting | No figure | No figure | 2% |
| Drivetrain | 1% | No figure | No figure |
| Steering | No figure | 1% | No figure |
| Corrosion | 0% | 0% | 1% |
Based on diesel cars in the 2017-2020 build-year band, from 69 to 126 cars at each age.
C257 variants compared
Most common issues on Mercedes-Benz CLS models of this age
This list covers every Mercedes-Benz CLS built around 2018, whichever generation it is. We don't have a defect list for the C257 on its own.
Most common advisories and fails
In order of the share of MOT tests that recorded each one
- 117.4%Advisory
Tyre worn close to the legal limit or worn on the edge
- 29.2%Advisory
Tyre slightly damaged, cracking or perishing
- 38.5%Advisory
Brake pads wearing thin
- 47.7%Advisory
Brake disc worn, pitted or scored, but not seriously weakened
- 54.8%Advisory
Tyre has a cut that does not reach the ply or cords
Based on 1,155 tests
Looking at a Mercedes-Benz CLS C257?
Enter its number plate to see its full MOT history, risk rating and running costs.
Frequently asked questions
Built around 2018 (7 years old), the Mercedes-Benz CLS C257 (2018-2024) fails MOTs noticeably less often than typical for this age. This is based on 612 7-year-old MOT tests from DVSA data. Each retest counts as a test.