2021 Mercedes-Benz C-Class
The 2021 Mercedes-Benz C-Class is sold in the U.S. as a gas compact sedan with 15 EPA-rated configurations. The most efficient version, the C300, is EPA-rated at 27 mpg combined. NHTSA lists 7 recall campaigns for this model year, which gives it a Safety Signal grade of D. Owners have filed 17 complaints, most often about the engine. NHTSA crash-tested it at 5 stars overall.

Specs & fuel economy
Source: EPA fueleconomy.gov| Configuration | Powertrain | Drive | Engine / motor | City | Hwy | Comb | Annual fuel* |
|---|---|---|---|---|---|---|---|
| C300 | Gas | RWD | 2.0L 4-cyl turbo | 23 | 35 | 27 | $3,050 |
| C300 4matic | Gas | 4WD | 2.0L 4-cyl turbo | 23 | 33 | 27 | $3,050 |
| C300 Coupe | Gas | RWD | 2.0L 4-cyl turbo | 24 | 33 | 27 | $3,050 |
| C300 4matic Coupe | Gas | 4WD | 2.0L 4-cyl turbo | 23 | 32 | 26 | $3,150 |
| C300 Convertible | Gas | RWD | 2.0L 4-cyl turbo | 23 | 31 | 26 | $3,150 |
| C300 4matic Convertible | Gas | 4WD | 2.0L 4-cyl turbo | 22 | 30 | 25 | $3,300 |
| AMG C43 4matic Convertible | Gas | 4WD | 3.0L 6-cyl turbo | 19 | 27 | 22 | $3,750 |
| AMG C43 4matic Coupe | Gas | 4WD | 3.0L 6-cyl turbo | 19 | 27 | 22 | $3,750 |
| AMG C43 4matic | Gas | 4WD | 3.0L 6-cyl turbo | 18 | 27 | 21 | $3,900 |
| AMG C63 | Gas | RWD | 4.0L 8-cyl turbo | 17 | 26 | 21 | $3,900 |
| AMG C63 S | Gas | RWD | 4.0L 8-cyl turbo | 17 | 26 | 21 | $3,900 |
| AMG C63 Convertible | Gas | RWD | 4.0L 8-cyl turbo | 17 | 25 | 20 | $4,100 |
| AMG C63 Coupe | Gas | RWD | 4.0L 8-cyl turbo | 17 | 26 | 20 | $4,100 |
| AMG C63 S Convertible | Gas | RWD | 4.0L 8-cyl turbo | 17 | 25 | 20 | $4,100 |
| AMG C63 S Coupe | Gas | RWD | 4.0L 8-cyl turbo | 17 | 26 | 20 | $4,100 |
*EPA estimate at 15,000 miles/year at EPA reference fuel and electricity prices. fueleconomy.gov record ids: 43515, 43348, 43332, 43333, 43335, 43334, 43528, 43527, 43535, 43531.
Emissions & certification
Source: EPA emission certificates| Configuration | Smog rating | Emission standard | Where it can be sold new | SmartWay |
|---|---|---|---|---|
| C300, C300 4matic, C300 4matic Convertible, C300 4matic Coupe, C300 Convertible, C300 Coupe | 6 / 10 | California LEV-III ULEV50 / Federal Tier 3 Bin 50 | All 50 states (federal, all altitudes); California and states following California standards | — |
| AMG C43 4matic, AMG C43 4matic Convertible, AMG C43 4matic Coupe | 5 / 10 | California LEV-III ULEV70 / Federal Tier 3 Bin 70 | All 50 states (federal, all altitudes); California and states following California standards | — |
| AMG C63, AMG C63 Convertible, AMG C63 Coupe, AMG C63 S, AMG C63 S Convertible, AMG C63 S Coupe | 3 / 10 | Federal Tier 3 Bin 125 | All 50 states (federal, all altitudes); California and states following California standards | — |
Certified for all fifty states, so it can be registered new anywhere in the U.S.
The smog rating scores tailpipe pollutants other than greenhouse gases, 1 (worst) to 10 (best), and is comparable only within a model year. The standard is the federal bin or California tier the configuration was certified to. Both come from the EPA certificate behind the window sticker.
Specifications filed with NHTSA
Source: NHTSA vPICDimensions Exterior
| Body style | Sedan/Saloon |
| Doors | 4 |
| GVWR class | Class 1: 6,000 lb or less (2,722 kg or less) |
Engine Basics
| Cylinders | 6 |
| Displacement | 3 L |
| Engine configuration | V-Shaped |
Fuel Economy
| Fuel | Gasoline |
Seating
| Seat rows | 2 |
| Seating capacity | 5 seats |
Transmission
| Transmission | Automatic |
| Transmission speeds | 9 |
Driver assistance
Standard: Anti-lock brakes, Automatic emergency braking, Backup camera, Blind-spot monitoring, Electronic stability control, Forward collision warning
Optional: Adaptive cruise control, Lane departure warning, Lane keeping assist, Parking assist
Filed by the manufacturer with NHTSA under the federal vehicle-identification rule and decoded from the VIN pattern — not a manufacturer press kit, so it describes the configurations we could identify rather than every trim (seen: AMG C43, AMG C63 S, C300, C300-4M). Figures for the trim you are looking at may differ.
Dimensions & weight
Source: Transport Canada| Length | 184.6–187.4 in |
| Width (body, without mirrors) | 71.3 in |
| Height | 55.1–57.5 in |
| Wheelbase | 111.8 in |
| Track, front | 61.4–62.6 in |
| Track, rear | 61.0–62.2 in |
| Curb weight | 3,583–4,275 lb |
| Weight distribution, front/rear | 51/49 to 55/45 |
Measured by Transport Canada for its Canadian Vehicle Specifications database, which covers the North American versions of each model — here 11 configurations: AMG C 63 S 2-door Convertible, AMG C 63 S 2-door Coupe, C 300 4Matic 4-door Sedan, C 300 4Matic 4-door Wagon, C 43 AMG 4Matic 4-door Sedan, C 43 AMG 4Matic 4-door Wagon …. Where a range is shown, those versions differ. Width is the body without mirrors, which is why it can read narrower than a brochure figure. Before we used it we checked it against the US manufacturer press kits we hold (27 Sep 2026): wheelbase agreed within 1% on every vehicle we could compare, length on 98%, and the curb weight fell inside the manufacturer's range on 96%. Source dataset. Contains information licensed under the Open Government Licence – Canada. Licence.
Factory warranty running out?
The 2021 Mercedes-Benz C-Class is in the years where transmission, electronics and drivetrain repairs land on the owner. What an extended plan does and does not cover is worth reading before a dealer quotes you one.
What to check before you buy →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
Recalls (7)
Source: NHTSA recall databaseElectrical System
See Recall ScheduleBack Over Prevention
2022060007Seats
2021060010Seats
2021040016Electrical System
2021020025Seat Belts
2021020010These are vehicle campaigns — the ones the automaker filed against this model. NHTSA also records equipment recalls, filed by a parts maker against a component (a tyre, a child seat, an aftermarket part), and those are not listed here or counted above. nhtsa.gov/recalls shows both for a VIN.
Whether any of this applies to one specific C-Class
A campaign covers a build range, not a model year, so two identical-looking cars from 2021 can differ. Both of these check a VIN against the manufacturer’s own list, free, in about ten seconds. Mercedes-Benz publishes its own lookup because federal rule 49 CFR 573.15 requires it to, and to keep it current to within seven days.
Hear about a recall before the letter does
The manufacturer’s letter is the last step of a recall: it has up to 60 days after filing to mail owners, at the address on the registration. We email you the day NHTSA posts a recall on the 2021 Mercedes-Benz C-Class, with what to do next. Nothing else, ever — no newsletter, no marketing, one-click unsubscribe in every message.
Parts & accessories for the 2021 Mercedes-Benz C-Class
Search by fitment on eBay Motors — OEM take-offs, aftermarket, and the trim pieces dealers no longer stock. The listing and the price are the seller's.
Find parts for this C-Class →Owner complaints
Source: NHTSA complaint database0 involved a crash · 0 a fire · 0 injuries · 0 deaths reported
5.3 per 10,000 built · Mercedes-Benz reported 32,134 C-Class built (its Early Warning production report to NHTSA)
Filed per year: 2022: 1 · 2023: 2 · 2024: 3 · 2025: 7 · 2026: 4
Most-cited components
In owners' own words
Filed with NHTSA by the people who own these cars, one per problem area. Quoted as written, with anything identifying removed.
The contact owns a 2021 Mercedes-Benz C 300. The contact stated that while depressing the accelerator pedal, there was a loud knocking sound coming from the engine compartment while accelerating. There were no warning lights illuminated.
The contact owns a 2021 Mercedes Benz C. The contact stated that while driving on the highway, the vehicle began to lose power, riding rough. The check engine light illuminated. The vehicle was towed to the dealer where it was diagnosed with a fuel injection failure. The vehicle read diagnostic code P1CEF85.
Driving and something came from underneath the vehicle and cause me to swerve in all the airbags deployed
Both driver and passenger seatbelts do not fully retract and remain loose. Must be manually guided back into mechanism. I see that there has been a recall for the cabriolet version of this vehicle platform but not for the coupe version.
I am reporting a safety defect involving the panoramic sunroof on my 2021Mercedes-Benz Coop vehicle. The panoramic sunroof has malfunctioned due to an apparent design or manufacturing defect. The sunroof fails to open / close and makes grinding or popping noises which malfunctioned unexpectedly.
The contact owns a 2021 Mercedes-Benz C43 AMG equipped with Continental Tires, Tire Line: Sport Contact, Tire Size: 225/40/R19, DOT Number: LMJAD5UR (Front Tires) and Pirelli Tires, Tire Line: P Zero, Tire Size: 225/40/R19, DOT Number: 93X2Y082 (Rear Tires).
Complaint counts are raw owner reports to NHTSA, not verified defects, and scale with how many were sold. Use them to spot patterns, not to rank.
Reported by Mercedes-Benz itself: 5 death-or-injury claims on this model year in its quarterly Early Warning reports to NHTSA (49 CFR 579.21): 6 injured, as claimed, not verified — about 16 per 100,000 built. Every C-Class model year, by year and system → Dated and by system, they are exhibit F of the defect dossier.
Crash ratings
Source: NHTSA NCAP| Configuration | Overall | Frontal | Side | Rollover | Rollover risk |
|---|---|---|---|---|---|
| 4 DR 4WD | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★☆ | 11% |
| 4 DR RWD | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★☆ | 11% |
NHTSA New Car Assessment Program.
Service bulletins & campaigns
Source: NHTSA manufacturer communications- 15 years or 150,000 miles, whichever comes first · Mercedes-Benz bulletin CL - EW M264Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the…
- 15 years or 150,000 miles, whichever comes first · Mercedes-Benz warranty extension EW - Cylinder Head M264In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC is extending the warranty coverage on the…
- 10 years or 120,000 miles, whichever comes first · Mercedes-Benz bulletin CL - 05012025In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for the…
The term and the vehicles it covers are the manufacturer’s, as NHTSA’s summary of each filing states them; a dealer checks one particular car by its VIN. Every Mercedes-Benz warranty extension (9) → · Every warranty extension on file, all makes →
Most often about: Electrical System, Power Train, Engine, Equipment, Structure.
- LI46.10-P-080896 Service bulletin2026-09-26 · Steering
- Complaint Slight creaking noises when steering. Cause Noises may come from one or more sleeves of the horn contact plate. Remedy Remove the horn contact plate and check the sleeves for noise; see attached video. If necessary, apply lubricant to the sleeves.
- LI27.00-P-073124 Service bulletin2026-09-26 · Power Train
- Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G‑TRONIC automatic transmission facelift) For faster, more effective and more targeted diagnosis, Intelligent Predictive Repair (IPR) has been developed and integrated into XENTRY Diagnosis. This ensures an automated diagnosis process. Cause As part of t
- LI83.90-P-080935 Service bulletin2026-09-25 · Visibility/Wiper
- Complaint CEL illuminates and/or AC does not blow cold. Cause Potentially relevance to hardware and/or software Remedy Scenario 1: 1. If the AC does not blow cold air, replace compressor (if compressor's index and part number Figure 1 match against Table 1). a. If the compressor does not fall within Table 1, please open a TIPS case. b. Flush procedure must be followed as per WIS. Scenario 2: 1. If
- LI42.10-P-078779 Service bulletin2026-09-22 · Service Brakes
- Complaint Repeat workshop visit for vehicle vibration while braking from 60MPH. NOTE: Although the symptom is similar to a tire or wheel vibration, it is usually readily noticeable that it is distinctly different if it happens at all times or only while braking. Cause Although the cause of the vibration is most likely due to excessive lateral runout on the rotor or hub/wheel bearing, the system as
- LI82.62-P-078631 Service bulletin2026-09-14 · Structure — Body
- Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Note: Please refer to this document i
- LI27.10-P-075869 Service bulletin2026-09-14 · Power Train
- Complaint Only vehicles with a variable transfer case are affected. This can be identified through control unit N45 or N15/7 in the quick test. When accelerating with light load, vibrations or jolting sensation may come from the drivetrain. It may be mistaken for a harsh shift. Cause Modified oil quality of the transfer case over time Remedy 1. Check initial quick test for faults in the following
- LI27.00-P-073124 Service bulletin2026-09-04 · Power Train
- Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic / 9G‑TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G‑TRONIC automatic transmission facelift) For faster, more effective and more targeted diagnosis, Intelligent Predictive Repair (IPR) has been developed and integrated into XENTRY Diagnosis. This ensures an automated diagnosis process. Cause As part of
- LI42.10-P-063502 Service bulletin2026-09-01 · Service Brakes
- Complaint Noises/ squealing from the service brake in various driving situations and ambient conditions. Cause Frictional vibrations Remedy The intent of this document is to reduce noise from high performance AMG brakes. AMG brakes are designed for performance under high load and in certain scenarios, can emit noise. Some scenarios are normal and some are induced by driving style like those listed
A service bulletin is the manufacturer telling its dealers how to diagnose or repair a known condition. It is not a recall, not a finding that the vehicle is defective, and the work is not automatically free — though a bulletin is often what a dealer works from when you describe a symptom, so quoting the document number can save a diagnosis. The count is every communication filed; the list shows the most recent, one entry per campaign, because a single campaign is usually filed as several documents on the same day. The summaries are NHTSA's; the full documents come from the manufacturer.
At the New York inspection station
Source: New York State DMVIn New York’s inspection lanes over the 12 months to Oct 10, 2026, the 2021 Mercedes-Benz C-Class failed the emissions check on 1.0% of first inspections — lower than the 1.9% for every 2021 model-year vehicle inspected; and the safety inspection on 0.72% (every 2021 vehicle: 1.5%).
failed emissions
1,384 initial inspections of 1,365 vehicles.
| Measure | The 2021 C-Class | Every 2021 vehicle | Behind it |
|---|---|---|---|
| Failed the emissions check | 1.0% | 1.9% | 1,379 |
| Failed the safety inspection | 0.72% | 1.5% | 1,384 |
| Air-bag warning lamp stayed lit | 0.14% | 0.19% | 1,384 |
| Miles driven a year | 7,110 | 10,343 | odometer at inspection |
| Average odometer | 37,728 | 54,681 | odometer at inspection |
New York’s emissions test on these model years is an on-board diagnostics check: it fails a car whose check-engine light is on or whose self-tests have not finished. First inspections only, so a car that failed and came back is counted once; private and special plates, not taxis, livery or commercial plates. A rate appears only where at least 200 inspections stand behind it. “Every 2021 vehicle” is every 2021 model-year car, SUV and pickup inspected in the same window, all makes. This is the state’s record of test results, not a reliability score by itself. Source: New York State Department of Motor Vehicles, Vehicle Inspections (data.ny.gov, Open NY terms).
C-Class by model year
all years, side by side →Common questions about the 2021 C-Class
Source: EPA, NHTSA and manufacturer press kitsDoes the 2021 Mercedes-Benz C-Class have any recalls?
NHTSA has posted 7 recall campaigns for the 2021 Mercedes-Benz C-Class. The most serious on file is 23V445000, covering Fuel System, Gasoline. Check your own VIN at nhtsa.gov/recalls; a recall applies to specific build ranges, not every car.
How safe is the 2021 Mercedes-Benz C-Class?
NHTSA gave the 2021 Mercedes-Benz C-Class 5 stars overall in its New Car Assessment Program tests — 4-star frontal crash, 5-star side crash, 4-star rollover. WhichTrim also grades it D (68/100) on its recall record, which is a different question from crash protection.
What is the fuel economy of the 2021 Mercedes-Benz C-Class?
Across the 15 EPA-rated configurations of the 2021 Mercedes-Benz C-Class, the best EPA combined figure is 27 mpg. Figures are the EPA's own, per configuration, and every one is listed above.
What are the dimensions of the 2021 Mercedes-Benz C-Class?
Transport Canada measured it at 184.6–187.4 in long, 71.3 in wide (body, without mirrors), 55.1–57.5 in tall, on a 111.8 in wheelbase. Curb weight: 3,583–4,275 lb depending on configuration. Those are its measurements of the North American versions; every figure is in the table above.
What do owners complain about on the 2021 Mercedes-Benz C-Class?
Owners have filed 17 complaints with NHTSA about the 2021 Mercedes-Benz C-Class, most often about engine, fuel/propulsion system, air bags. Complaints are unverified owner reports, so treat the pattern as a signal and the individual report as an anecdote.
How clean is the 2021 Mercedes-Benz C-Class?
The EPA smog rating for the 2021 Mercedes-Benz C-Class runs 3 to 6 out of 10 across its configurations. That score covers tailpipe pollutants other than greenhouse gases, and it only compares vehicles within the same model year. It is certified for all fifty states, so it can be registered new anywhere in the U.S. Its configurations were certified to different standards — California LEV-III ULEV50, California LEV-III ULEV70, Federal Tier 3 Bin 125, Federal Tier 3 Bin 50, Federal Tier 3 Bin 70 — which the table above lists per configuration.
Are there service bulletins for the 2021 Mercedes-Benz C-Class?
The manufacturer has filed 720 service bulletins and related communications with NHTSA for the 2021 Mercedes-Benz C-Class, most often covering electrical system, power train, engine. The most recent is dated 2026-09-26. A bulletin is not a recall: it is the repair procedure a manufacturer sends its dealers for a condition it knows about, and the work is not automatically paid for. It is still worth knowing — if the symptom matches, quoting the bulletin number at the service desk can save a diagnosis. The document numbers and summaries are listed above.
How does the 2021 Mercedes-Benz C-Class do at state inspection?
In New York’s inspection lanes over the 12 months to Oct 10, 2026, the 2021 Mercedes-Benz C-Class failed the emissions check on 1.0% of first inspections — lower than the 1.9% for every 2021 model-year vehicle inspected; and the safety inspection on 0.72% (every 2021 vehicle: 1.5%). The figures are New York State DMV’s own inspection records, first inspections only, and the table above sets each one against every vehicle of the same model year.
What we hold, and what an empty row means
Paid vehicle-history reports will not tell you the difference between “nothing happened to this car” and “we never received that record” — both of the big two say as much in their own help pages. Most of what is on this page comes from complete federal registers, so we can tell you which is which, row by row.
| Data | Held | Source | What it covers — or what empty means |
|---|---|---|---|
| Fuel economy & configurations | 15 configurations | EPA certification records | Every configuration the EPA certified for sale, with its own test figures. |
| Emission certificates | 15 configurations | EPA emission certificates | Smog rating, standard and the sales area that decides where the car can be sold new. |
| Recalls | 7 | NHTSA recall campaigns | A complete federal register: every campaign covering this model year, with severity and advisory flags. |
| Owner complaints | 17 | NHTSA complaint database | Also complete, but unverified: these are reports owners filed, not findings. Counts scale with how many were sold. |
| Crash ratings | 2 tested | NHTSA NCAP | Only the configurations NHTSA chose to crash-test, which is never all of them. |
| Service bulletins | 720 | NHTSA manufacturer communications | Everything the manufacturer told its dealers about a defect or malfunction, short of a recall. |
| Investigations | none | NHTSA Office of Defects Investigation | No defect investigation has been opened. |
| Driver-assist crash reports | none | NHTSA Standing General Order 2021-01 | No report has been filed. Only entities named in the order report, and only crashes they hear of — so this is also what an unequipped car, or a manufacturer without telematics, looks like. |
| Specifications filed with NHTSA | 11 fields | NHTSA vPIC, decoded from VIN patterns | What the manufacturer filed under the federal VIN rule — a configuration, not the full trim ladder. |
| Measured dimensions | 7 fields | Transport Canada, Canadian Vehicle Specifications | Length, width, height, wheelbase, track and curb weight, measured on the North American versions. |
| Trims, pricing & equipment | none | Manufacturer press kit | We have not transcribed a press kit for this model year yet. This is our gap, not the manufacturer's — the one row here where an empty cell means we are behind. |
Rebuilt nightly; this page was generated 2026-10-26. Every figure above is traceable to the source named beside it, and the JSON for this page carries the same values with their identifiers.
Sources & method
Safety Signal starts every model-year at 100 and subtracts points per open NHTSA recall campaign by severity: critical 15 (fire risk, park-outside or do-not-drive advisories), high 8 (brakes, steering, airbags, loss of drive power, structure, battery), moderate 6, minor 3 (software, labels, lighting fixed by an update). The most serious recall counts in full and each further one counts 85% of the one before, because a vehicle sold in millions is recalled more often than a rare one without being more dangerous — and because a flat subtraction bottomed the scale out, scoring a vehicle with 22 recalls within a point of one with six. A ≥ 90, B ≥ 80, C ≥ 70, D ≥ 60, otherwise F. Read it as what it counts: recall campaigns on the federal record, weighted by severity. The damping reduces the sales bias by roughly 40% but does not remove it: like our complaint counts, this is not normalized by how many were sold, so a best-seller still scores somewhat worse than an obscure model with the same real risk. NHTSA crash ratings, do-not-drive and park-outside advisories, and the crash, fire, injury and death counts in owner complaints are reported separately on every page and never blended into the letter — a vehicle can hold five stars and a poor letter at once, and where that happens we say so rather than leave you to notice. Because the scale subtracts from a clean sheet, a model year too new to have been recalled, complained about or bulletined scores full marks on an empty record; we label those grades provisional rather than present them as earned.
EPA figures come from fueleconomy.gov vehicle records. Recalls, complaints, investigations and crash ratings come from NHTSA's public flat files, refreshed nightly.