Is the 2018 Mercedes-Benz C 300 reliable?

The 2018 Mercedes-Benz C 300 has 128 complaints filed with NHTSA (3.3x the segment average). Our reliability verdict: avoid. Most common issue: ENGINE problems.

What are common problems with the 2018 Mercedes-Benz C 300?

Top problems: ENGINE (35 complaints, avg repair $500); OTHER (24 complaints, avg repair $500); BODY/STRUCTURE (12 complaints, avg repair $500). Issues typically appear around 50K miles.

Are there any recalls on the 2018 Mercedes-Benz C 300?

Yes, there are 18 recall(s): ELECTRICAL SYSTEM:SOFTWARE, ELECTRICAL SYSTEM:SOFTWARE, STRUCTURE:BODY:ROOF AND PILLARS, SEATS, AIR BAGS:FRONTAL, SEAT BELTS:FRONT:RETRACTOR, COMMUNICATION, SEATS, EXTERIOR LIGHTING:HEADLIGHTS, STRUCTURE:BODY:ROOF AND PILLARS, AIR BAGS:SENSOR:OCCUPANT CLASSIFICATION, STEERING:RACK AND PINION:RACK, EXTERIOR LIGHTING:HEADLIGHTS, ELECTRICAL SYSTEM:12V/24V/48V BATTERY, STRUCTURE:BODY, VISIBILITY:GLASS, SIDE/REAR, ELECTRICAL SYSTEM:12V/24V/48V BATTERY:CABLES, STEERING. Contact any Mercedes-Benz dealer to verify if recalls have been completed on your specific vehicle.

How much does it cost to fuel a 2018 Mercedes-Benz C 300?

The 2018 Mercedes-Benz C 300 gets 27 MPG combined. At current US average gas prices, driving 12,000 miles per year costs roughly $1778. See the interactive fuel cost calculator on this page for state-specific pricing.

How much does it cost to insure a 2018 Mercedes-Benz C 300?

Estimated US average full-coverage insurance for the 2018 Mercedes-Benz C 300 is approximately $2,143/year (sedan-luxury class). Actual quotes vary heavily by state, driver age, driving record, and credit — see the interactive insurance estimator on this page for state-specific pricing.

2018 Mercedes-Benz C 300

Problems, Recalls & Reliability Report

Avoid This Year

Quick Summary

The 2018 Mercedes-Benz C 300 has 128 owner complaints filed with NHTSA — that's 3.3x the segment average of 39. The most common issue is engine problems (27% of all complaints), specifically: tl* the contact owns a 2018 mercedes-benz c300. while operating the vehicle, the contact noticed a burnt crayon odor inside the vehicle. the odor made it difficult to breathe inside the vehicle. the vehicle was taken to mercedes-benz of goldens bridge (321 ny-22, goldens bridge, ny 10526), but the c. There are 18 recalls issued for this model year.

8 crash reports 2 injuries

128

Total Complaints

Recalls Issued

—/5

Safety Stars

3.3x

vs Segment Avg

Known Problems(top 5 of 8)

ENGINE

35 complaints

27%

• TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ C300. WHILE OPERATING THE VEHICLE, THE CONTACT NOTICED A BURNT CRAYON ODOR INSIDE THE VEHICLE. THE ODOR MADE IT DIFFICULT TO BREATHE INSIDE THE VEHICLE. THE VEHICLE WAS TAKEN TO MERCEDES-BENZ OF GOLDENS BRIDGE (321 NY-22, GOLDENS BRIDGE, NY 10526), BUT THE C
• WHEN AT A STOP THE ENGINE WILL NOT RESTART SOMETIMES. I HAVE TO START THE ENGINE MANUALLY. THIS HAS HAPPENED TO ME FOUR TIMES IN 5 MONTHS .
• CYLINDER 1 SPARK PLUGS IS DAMAGED DUE TO PISTON DAMAGE, HOLE IN PISTON. IF EXTRA DAMAGE IS FOUND ON TEAR DOWN, COMPLETE ENGINE REPLACEMENT. This is direct from the repair facilities reports. While driving my 2018 C-300 there was smoking out of tail pipe, a rough vibration, hard to control the vehic

Typical onset: 50K miles Est. repair: $500

“TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ C300. WHILE OPERATING THE VEHICLE, THE CONTACT NOTICED A BURNT CRAYON ODOR INSIDE THE VEHICLE. THE ODOR MADE IT DIFFICULT TO BREATHE INSIDE THE VEHICLE. THE VEHICLE WAS TAKEN TO MERCEDES-BENZ OF GOLDENS BRIDGE (321 NY-22, GOLDENS BRIDGE, NY 10526), BUT THE C”

— NHTSA complaint filing

When Problems Appear on the 2018 Mercedes-Benz C 300

Based on 29 owner complaints that included an odometer reading. Median mileage at time of complaint: 50K miles. Most complaints cluster in the 0-30K miles range.

Overall complaint distribution by mileage

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

BODY/STRUCTURE

In line with typicalmedian 45K mi · 5 reports

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

Mileage figures are self-reported by owners in NHTSA complaint filings. Peak bucket = the mileage range with the most complaints for that component; it reflects when owners noticed and reported problems, not necessarily when the fault first occurred.

Recalls (18)

ELECTRICAL SYSTEM:SOFTWARE05/02/2021

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. The software design of the communication module may fail to communicate the correct vehicle location for the emergency call system (eCall) in the event of a crash.

Risk: Failure of the eCall system may result in emergency responders being dispatched to the wrong location, increasing the risk of injury following a crash.

Fix: 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. Owners may contact MBUSA customer service at 1-877-762-8267. MBUSA's number for this recall is 2021020025.

Fuel Cost Calculator for 2018 Mercedes-Benz C 300

Live EIA prices

Annual miles driven: 12,000

Your state (affects local gasoline price)

Per year

$1,778

Per month

$148

Per mile

14.8¢

MPG

City driving (worst-case MPG)

$2,001/yr

Highway driving (best-case MPG)

$1,455/yr

Based on EPA fuel-economy ratings and EIA weekly retail prices (2026-07-20). Real-world cost varies with driving style, trim/engine, terrain, and traffic.

5-Year Gas Price History

EIA weekly retail data · 2021 → today

Show:

Current

$4.00

5-year low

$2.78

5-year high

$5.01

Since 2021

+27%

Source: US Energy Information Administration weekly retail gasoline prices.

Estimated Insurance Cost for 2018 Mercedes-Benz C 300

Estimate only, not a quote. Modeled from NAIC + HLDI averages for a hypothetical 35-year-old driver with clean record + full coverage. Your actual quote depends heavily on your age, driving history, credit, ZIP code, and insurer.

Your state (affects local premium average)

Full coverage / year

$2,143

Full coverage / month

$179

Liability only / year

$710

vs US avg

+28%

How this estimate is calculated

US base full-coverage premium$1674

× state (US)1.00x

× vehicle class (sedan-luxury)1.28x

× theft risk1.00x

× safety rating1.00x

× vehicle age1.00x

= Full coverage estimate$2143

Coverage assumed: 100/300/100 liability + comprehensive/collision, $500 deductibles. Data sources: NAIC 2024 + HLDI loss studies.

Maintenance & Warranty

Recommended Mercedes-Benz C 300 Service Intervals

Oil change

10K mi / 12 mo

Tire rotation

10K mi

Brake fluid

24 months

Transmission fluid

40K mi

Engine coolant

150K mi

Spark plugs

60K mi

Cabin air filter

20K mi

Engine air filter

40K mi

Differential (AWD/4WD)

40K mi

Service A / Service B alternating schedule. Requires MB-approved oil (229.5 spec typically).

"Severe service" conditions (heavy towing, extreme temps, city stop-and-go) typically halve these intervals. Always consult your vehicle's owner's manual for the authoritative schedule.

Mercedes-Benz New-Vehicle Warranty Coverage

Bumper-to-bumper (basic)

4 yr / 50K mi

Powertrain

4 yr / 50K mi

Hybrid/EV battery

10 yr / 155K mi

Corrosion (rust perforation)

4 yr / 50K mi

Roadside assistance

4 yr / unlimited mi

EQ EV battery warranty is 10 years/155,000 miles

These are the terms for a new Mercedes-Benz. If you're buying a used 2018 C 300, remaining coverage is usually pro-rated from the vehicle's original in-service date. Not all coverage transfers between owners — check with a Mercedes-Benz dealer for VIN-specific remaining warranty.

Estimated Repair Costs

ENGINE(~50K mi)

$500

OTHER(~50K mi)

$500

BODY/STRUCTURE(~50K mi)

$500

STEERING(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

Estimates based on average reported repair costs. Actual costs vary by location, shop, and severity.

🔍 Pre-Purchase Inspection Checklist

Based on 128 owner complaints for this specific year, here's what to check or ask about:

☐
ENGINE: TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ C300. WHILE OPERATING THE VEHICLE, THE CONTACT NOTICED A BURNT CRAYON ODOR INSIDE THE VEHICLE. THE ODOR MADE IT DIFFICULT TO BREATHE INSIDE THE VEHICLE. THE VEHICLE WAS TAKEN TO MERCEDES-BENZ OF GOLDENS BRIDGE (321 NY-22, GOLDENS BRIDGE, NY 10526), BUT THE C
Typically appears around 50K miles. Repair cost ~$500
☐
OTHER: FORWARD COLLISON SYSTEM ($1700 OPTION) AEB, DOES NOT WORK AS DESCRIBED IN MB LITERATURE OR WEBSITE. IN MY OPINION, THE FORWARD COLLISION AVOIDANCE SYSTEM (AEB) IN MY 7 MO. OLD 2018 MERCEDES C300 SIMPLY DOES NOT WORK. I SPECIAL ORDERED THE CAR WITH THE 997 PKG THAT INCLUDES, DRIVER ASSISTANCE, BAS+,
Typically appears around 50K miles. Repair cost ~$500
☐
BODY/STRUCTURE: TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ C300. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 18V456000 (STRUCTURE); HOWEVER, THE PARTS TO DO THE REPAIR WERE UNAVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR AS THE RECALL N
Typically appears around 50K miles. Repair cost ~$500
☐
STEERING: I AM WRITING TO SHARE MY DISSATISFACTION WITH MERCEDES BENZ. I HAVE A 2018 C300 THAT WAS PURCHASED BRAND NEW. THE STEERING WHEEL IS DETERIORATING AND I ADDRESSED THE SERVICE DEPARTMENT OF ONTARIO,CA. I OPENED A CASE WITH CORPORATE AND SPOKE WITH CASE MANAGER JAMES WHO WAS NOT HELPFUL, AND REFUSED TO
Typically appears around 50K miles. Repair cost ~$500
☐
RECALLS: Verify all 18 recalls have been completed — free at any Mercedes-Benz dealer
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)