2018 Mercedes-Benz C300 — Full Specifications
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The 2018 Mercedes-Benz C300 is a saloon/sedan powered by a 2L 4-cyl turbo premium gasoline engine. Its most fuel-efficient configuration returns around 32 mpg (UK) / 27 mpg (US EPA) combined, with 31–32 mpg (UK) across all configurations. Owners often keep a Mercedes-Benz C300 workshop manual to hand for servicing and repairs.
Compared with the 2017 Mercedes-Benz C300: Fuel economy slips from 34 to 32 mpg (UK) combined on the most efficient configuration. The engine line-up listed by EPA is unchanged. It carries the same 5★ overall NHTSA rating.
Full Specifications
| Engine | 2L 4-cyl turbo |
|---|---|
| Transmission | Automatic 9-spd |
| Fuel Type | Premium Gasoline |
| Powertrain | Conventional |
| Drive | Rear-Wheel Drive |
| Body Style | Saloon/Sedan |
| Passenger Volume (EPA) | 90 cu ft (2,549 L) |
| Luggage Volume (EPA) | 13 cu ft (368 L) |
| Fuel Economy (UK) | 32 combined / 29 urban / 40 extra-urban mpg |
| Fuel Economy (US EPA) | 27 combined / 24 city / 33 highway mpg |
| CO₂ Emissions | 201 g/km |
| EPA Greenhouse Gas Score | 5 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,050 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2018 Mercedes-Benz C300, all with the 2L 4-cyl turbo engine. Combined fuel economy ranges from 26 to 27 mpg (US), or 31 to 32 mpg (UK), depending on engine, transmission and drive. The headline figures at the top of this page describe the most fuel-efficient configuration.
| Engine | Transmission | Drive | MPG (UK) | MPG (US) | CO₂ g/km | Fuel cost / yr |
|---|---|---|---|---|---|---|
| 2L 4-cyl turbo | Automatic 9-spd | 4-Wheel Drive | 31 | 26 (23/32) | 208 | $3,150 |
| 2L 4-cyl turbo | Automatic 9-spd | Rear-Wheel Drive | 32 | 27 (24/33) | 201 | $3,050 |
MPG (US) shows combined, with city/highway in brackets. Highlighted row = the configuration used for the headline figures. Source: US EPA fueleconomy.gov.
EPA measures interior passenger volume at 90 cubic feet (about 2,549 litres) and luggage volume at 13 cubic feet (about 368 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2018 Mercedes-Benz C300
Running Costs: 2018 Mercedes-Benz C300
Covering around 8,000 miles a year in a 2018 Mercedes-Benz C300 at 32 mpg combined, expect roughly 1,136 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,050 a year in fuel for the most efficient configuration (15,000 miles, national average prices). Work out exact fuel costs with the fuel cost calculator on 247Calculators.
Convert between MPG and L/100km with the unit converters on 247QuickTools. Not sure what tyre size fits? 247TyreCheck explains tyre sizing.
Only need this car occasionally? See our buy vs rent comparison.
2018 Mercedes-Benz C300 Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists no safety recall campaigns for the 2018 Mercedes-Benz C300 as of 6 October 2026. Recalls can be issued years after a model is sold, so it is still worth checking your own VIN.
Owners have filed 130 complaints with NHTSA about the 2018 Mercedes-Benz C300. The most-reported areas are Engine (39), Unspecified (27), Structure (19). Complaints include 5 reported crashes, 2 reported injuries. That is close to the median of 130 complaints across the 17 Mercedes-Benz C300 model years in our data.
Used-buyer checklist for the 2018 Mercedes-Benz C300
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Engine (39 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
- Body structure (19 owner complaints) — Inspect for corrosion and for subframe or body-panel damage, especially underneath.
- Steering (13 owner complaints) — Check for play, noise or heavy steering, and ask whether any steering recall work was done.
Source: US NHTSA recall and consumer-complaint databases, retrieved 6 October 2026. Complaints are unverified owner reports, not confirmed defects. Check any vehicle by VIN at nhtsa.gov/recalls, and see our guide to checking a used car for recalls.
How It Compares
Mercedes-Benz models in our database average about 26 mpg (UK) combined on their most efficient configuration; the 2018 Mercedes-Benz C300's 32 mpg is 6 mpg above that make average. Its 201 g/km CO₂ figure is 67 g/km lower than the 268 g/km Mercedes-Benz average.
Of the 17 Mercedes-Benz C300 model years we cover, the 2018 ranks 10th for combined fuel economy on its best configuration (32 mpg UK combined, against a high of 36 mpg). See every Mercedes-Benz C300 year side by side.
Last updated: · Data: US EPA (fueleconomy.gov) and NHTSA safety ratings 18 July 2026; NHTSA recalls and complaints 6 October 2026; Wikidata & curated EU catalogue 18 July 2026; European generation and engine data from Wikipedia 7 October 2026
Vehicle data sourced from manufacturer specifications. Always verify with your vehicle handbook or a qualified mechanic. This is a reference tool, not professional advice.
Recommended Accessories for the 2018 Mercedes-Benz C300
Frequently Asked Questions
What engine does the 2018 Mercedes-Benz C300 have?
It's fitted with a 2L 4-cyl turbo premium gasoline engine, paired with a automatic 9-spd transmission.
What is the fuel economy of the 2018 Mercedes-Benz C300?
The most efficient configuration returns around 32 mpg (UK) combined, or 27 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 31 to 32 mpg.
How much does the 2018 Mercedes-Benz C300 cost to fuel per year?
The US EPA estimates about $3,050 a year in fuel for the most efficient configuration, based on 15,000 miles of mixed driving and national average fuel prices. Your own cost will depend on mileage and local prices.
Does the 2018 Mercedes-Benz C300 have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 4 stars for frontal crash protection.
Does the 2018 Mercedes-Benz C300 have any recalls?
NHTSA lists no safety recall campaigns for the 2018 Mercedes-Benz C300 as of 6 October 2026. Recalls can be issued years after a model is sold, so it is still worth checking your own VIN.
What are the most common problems reported for the 2018 Mercedes-Benz C300?
Among the 130 owner complaints filed with NHTSA, the most-reported areas are Engine (39 complaints), Unspecified (27 complaints), Structure (19 complaints). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
How much interior and luggage space does the 2018 Mercedes-Benz C300 have?
EPA measures interior passenger volume at 90 cubic feet (about 2,549 litres) and luggage volume at 13 cubic feet (about 368 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.