Most common 2020 Mercedes-Benz C300 problems
Share of the 33 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mercedes-Benz C300 complaints by model year
Best C300 years: 2014, 2021, 2020. Years to avoid: 2009, 2008. Compare all years →
2020 Mercedes-Benz C300 recalls (9)
Structure › Body › Roof and pillars
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2014-2020 C-Class, CLA, GLA, S-Class, GLC, and GLE vehicles. Please refer to MBUSA's recall report for specific vehicle details. The front roof panel located between the windshield and the panoramic sunroof may not have been bonded correctly to the vehicle during a prior…
Remedy: Dealers will replace the front panel, free of charge. Owner notification letters were mailed on August 2, 2024. Owner notification letters will be mailed in phases, on, March 22,2024, and August 2, 2024.
Communication › Auto crash notification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2022 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, AMG GT-Class, C-Class, E-Class, S-Class, SL-Class, GLC-Class, CLS-Class, GLB-Class, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details.
Remedy: The communication module software will be updated through an Over-the-Air (OTA) update or by a dealer, free of charge. Owner notification letters were mailed July 8, 2022.
Back over prevention › Display function
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2018-2021 CLA-Class, GLE/GLS-Class, A-Class, C-Class, E-Class, E-Class Coupe/Convertible, GLA/GLB-Class, GLC-Class, and CLS-Class vehicles. Please refer to MBUSA's recall report for specific vehicle model details.
Remedy: Dealers will update the rearview camera software, free of charge. Owner notification letters were mailed July 15, 2022. Owners may contact MBUSA customer service at 1-800-367-6372.
Exterior lighting › Headlights
Mercedes-Benz LLC (MBUSA) is recalling certain 2018-2020 C300, 2019-2020 A220, AMG C43, AMG C63, 2020 GLE580, GLB250, 2020-2021 GLE450, GLE350, 2021 AMG GLE63, and AMG GLE53 vehicles. The LED headlights may have been incorrectly adjusted during a vehicle repair.
Remedy: Dealers will replace the LED headlights, free of charge. Interim letters notifying owners of the safety risk were mailed August 13, 2021. A second notice will be sent once the remedy is available.
Structure › Body › Roof and pillars
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2020 C300 Coupe, C43 Coupe AMG, C43 AMG, 2015-2020 C300, GLA250, 2016-2018 C350e, CLA45 Coupe AMG, 2015 C400, S65 AMG, 2015-2019 C63 AMG, 2016 C450, 2015-2016 GLA45 AMG, S600, 2016-2020 GLC300, 2017-2019 GLC43 AMG, GLE43 Coupe AMG, 2014-2019 CLA250 Coupe, 2014-2015 CLA45…
Remedy: Mercedes-Benz dealer will remove the bonded panel and will install a new front panel by following the detailed repair instructions and using the approved primer, cleaner and adhesive, free of charge.
Communication › Auto crash notification
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2016 - 2021 CLA-Class, GLA-Class, GLE-Class, GLS-Class, SLC-Class, A-Class, GT-Class, C-Class, E-Class, S-Class, CLS-Class, SL-Class, B-Class, GLB-Class, GLC-Class, and G-Class vehicles. Please refer to the Part 573 report for specific vehicle model details.
Remedy: MBUSA will notify owners, and the communication module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. The recall began March 12, 2021.
Show 3 more recalls
Seat belts › Front › Retractor
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2021 C300, 2017-2020 AMG C43, and AMG C63 vehicles. The front seat belts might not fully retract to their stowed position. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 208, "Occupant Crash Protection."
Remedy: MBUSA will notify owners, and dealers will check the retraction function of the front seat belts and adjust the damping foam within the B-pillars, as necessary, free of charge. The recall began February 26, 2021.
Engine and engine cooling › Engine › Gasoline › Turbo/supercharger
Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2020 C300, E350, and GLC300 vehicles equipped with turbocharged 4-cylinder gasoline engines. The screws that retain the turbocharger oil feed and return lines may not have been properly tightened, possibly resulting in an oil leak.
Remedy: MBUSA will notify owners, and dealers will inspect the turbocharger oil lines and tighten them as necessary, free of charge. The recall began August 17, 2020. Owners may contact MBUSA customer service at 1-800-367-6372.
Communication
Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2020 C300 Cabrio, C300 Cabrio 4MATIC, C300 Coupe, C43 AMG Cabrio 4MATIC, C43 AMG Coupe 4MATIC, C63S AMG Cabrio, CLS53 AMG 4MATIC, E350, E350 4MATIC, E450 Cabrio, E450 Cabrio 4MATIC, E450 Coupe, E450 Coupe 4MATIC, E450 4MATIC, E53 AMG Cabrio 4MATIC, GLC300 Coupe 4MATIC,…
Remedy: MBUSA will notify owners, and dealers will replace the communication module, free of charge. The recall began April 14, 2020. Owners may contact MBUSA customer service at 1-800-367-6372.
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 2020 Mercedes-Benz C300:
Front Roof Panel Detachment
On January 8, 2021, after ongoing review with Mercedes Benz, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) opened PE21-001 to assess allegations of front roof panel detachments while driving at highway speeds in certain 2015 Mercedes-Benz (Mercedes) C-Class vehicles.The subject front roof panel is a stationary panel composed of polycarbonate and is attached to the…
What 2020 Mercedes-Benz C300 owners say
Engine & cooling
The contact owns a 2020 Mercedes-Benz C300. The contact stated that while at a stop, the vehicle failed to accelerate as intended. There was no warning light illuminated. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 100,000.
I purchased this 2020 Mercedes-Benz C300 only two months ago and have driven it less than 3,000 miles. The Carfax report shows consistent maintenance and regular service history by prior owners. While driving, the check engine light came on and the vehicle began shaking and running roughly. Diagnostics by Peachtree Imports (10/03/2025) and later by Mercedes-Benz of Atlanta South confirmed Cylinder #2 failure on the M264 2.0L engine at only 26,589 miles. The dealer's report states: "Cylinder #2 mixture formation out of spec. Fault occurred due to worn exhaust valve seat. Cylinder head replacement required." Estimated repair cost: $10,470.66. This causes misfire, loss of power, and unsafe drivability. The failure matches Mercedes-Benz Technical Service Bulletin LI01.30-P-072328 (2021), which documents valve-seat leakage in M264 engines requiring head replacement. …
Driver assistance
The contact owns a 2020 Mercedes-Benz C300. The contact stated that suddenly the vehicle's sensors were illuminating and activating a warning stated that the sensors were defective. Many of the vehicle's sensors began to deactivate and malfunction. While reversing out of a parking space the rear view camera and sensor system failed causing the contact to crash into another vehicle. Both vehicles were damaged. A police report was filed. There were no injuries reported. The vehicle was not towed. The contact took the vehicle to a repair facility and stated that there was damage to the internal sensor and camera system. The contact took the vehicle to the dealer however the vehicle had not been diagnosed or repaired as of yet. The contact then received a recall notice NHTSA Campaign Number: 22V232000 (BACK OVER PREVENTION) however the VIN tool confirms remedy not yet available. …
The contact owns a 2020 Mercedes-Benz C300. The contact was reversing out of her driveway at 3 MPH, the contact was using her rearview camera. The contact stated that the image froze and she crashed into a parked vehicle with the rear passenger side bumper of her vehicle. The contacts bumper was scratched and dented. The other vehicle had sustained a large dent in the driver's side door. The contact stated no warning light was illuminated. The contact had taken the vehicle to a local repair and not a dealer or an independent mechanic. The vehicle had been repaired cosmetically. The manufacturer had not been informed of the failure. The contact had received the manufacturer recall letter and related the accident to NHTSA Campaign Number: 22V232000 (Back Over Prevention). The failure mileage was approximately 6500.
Body & structure
The contact owns a 2020 Mercedes-Benz C300. The contact stated that a section of the roof near the top of the windshield, between the sunroof, had detached and flown off the vehicle while driving 30 MPH in bumper-to-bumper traffic. The driver was able to grab the portion of the rubber gasket and pulled it into the vehicle through the driver's side front window. The roof was in three pieces. The contact turned on the hazard lights and was able to pull over safely to the side of the roadway. There were no warning lights illuminated. The contact was concerned about the failure potentially causing a road hazard under different circumstances. The vehicle was taken to an independent mechanic the next day who declined to service the vehicle and informed the contact it was an issue for the manufacturer. …
I own a 2020 Mercedes-Benz C300 equipped with a power trunk. On July 22, 2026, I took my vehicle to Annapolis Mercedes-Benz because the power trunk was repeatedly closing on its own while people were standing in the trunk opening. I specifically reported that the trunk was unexpectedly closing while I, my child, or another individual was loading or unloading the vehicle and expressed concern that someone could be injured. The dealership kept the vehicle for several hours but advised me that no malfunction could be found. I was told the trunk had been reset and that there were no problems with the vehicle. I also provided video evidence of the trunk malfunction by text message to my service advisor. On August 2, 2026, the exact same problem occurred. …
2020 Mercedes-Benz C300 engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 2.0L 4-cyl turbo | 9-speed automatic | RWD | 24 / 35 / 28 |
EPA ratings. Class: Compact car.
Frequently asked questions
Is the 2020 Mercedes-Benz C300 a good car?
Based on 33 owner complaints filed with NHTSA, the 2020 C300 rates better than average: 65% fewer complaints than a typical year of the C300 at the same age. It is one of the best C300 years by this measure. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2020 Mercedes-Benz C300?
The engine & cooling — 8 complaints, 24% of all complaints for this model year. Next are the driver assistance (6) and body & structure (4).
How many recalls does the 2020 Mercedes-Benz C300 have?
There are 9 recalls for the 2020 Mercedes-Benz C300, the most recent from December 15, 2023 (roof and pillars). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Mercedes-Benz C300?
The best years by complaints, compared at the same age, are 2014, 2021 and 2020. Years to avoid or approach with caution: 2009 and 2008. See the full Mercedes-Benz C300 years comparison.
At what mileage do 2020 Mercedes-Benz C300 problems happen?
The median mileage reported in complaints is about 29,000 miles; 64% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.