2018 Mercedes-Benz CLS550 — Full Specifications
As an Amazon Associate and CJ Affiliate and AWIN publisher we earn from qualifying purchases. Links below are affiliate links.
Running gear matters most — before anything else, UK: check tyre prices at TirendoUS: check wheel & tyre prices at WheelHero for this car's fitment.
The 2018 Mercedes-Benz CLS550 is a saloon/sedan powered by a 4.7L 8-cyl turbo premium gasoline engine. Its most fuel-efficient configuration returns around 25 mpg (UK) / 21 mpg (US EPA) combined, with 24–25 mpg (UK) across all configurations. Owners often keep a Mercedes-Benz CLS550 workshop manual to hand for servicing and repairs.
Compared with the 2017 Mercedes-Benz CLS550: Fuel economy is essentially unchanged at around 25 mpg (UK) combined. The engine line-up listed by EPA is unchanged.
Full Specifications
| Engine | 4.7L 8-cyl turbo |
|---|---|
| Transmission | Automatic 9-spd |
| Fuel Type | Premium Gasoline |
| Powertrain | Conventional |
| Drive | Rear-Wheel Drive |
| Body Style | Saloon/Sedan |
| Passenger Volume (EPA) | 92 cu ft (2,605 L) |
| Luggage Volume (EPA) | 11 cu ft (311 L) |
| Fuel Economy (UK) | 25 combined / 22 urban / 31 extra-urban mpg |
| Fuel Economy (US EPA) | 21 combined / 18 city / 26 highway mpg |
| CO₂ Emissions | 264 g/km |
| EPA Greenhouse Gas Score | 4 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,900 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 2 configurations for the 2018 Mercedes-Benz CLS550, all with the 4.7L 8-cyl turbo engine. Combined fuel economy ranges from 20 to 21 mpg (US), or 24 to 25 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 |
|---|---|---|---|---|---|---|
| 4.7L 8-cyl turbo | Automatic 9-spd | 4-Wheel Drive | 24 | 20 (17/25) | 276 | $4,100 |
| 4.7L 8-cyl turbo | Automatic 9-spd | Rear-Wheel Drive | 25 | 21 (18/26) | 264 | $3,900 |
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 92 cubic feet (about 2,605 litres) and luggage volume at 11 cubic feet (about 311 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 CLS550
Running Costs: 2018 Mercedes-Benz CLS550
Covering around 8,000 miles a year in a 2018 Mercedes-Benz CLS550 at 25 mpg combined, expect roughly 1,455 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,900 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 CLS550 Safety Ratings (NHTSA)
No NHTSA crash-test rating is on record for this model year. The NHTSA rates only a subset of vehicles each year; you can browse every rated vehicle on our NHTSA Safety Ratings hub.
How It Compares
At 25 mpg (UK) combined it sits close to the 26 mpg average for Mercedes-Benz models in our database.
Of the 9 Mercedes-Benz CLS550 model years we cover, the 2018 is the most economical on its best configuration (25 mpg UK combined). See every Mercedes-Benz CLS550 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 CLS550
Frequently Asked Questions
What engine does the 2018 Mercedes-Benz CLS550 have?
It's fitted with a 4.7L 8-cyl turbo premium gasoline engine, paired with a automatic 9-spd transmission.
What is the fuel economy of the 2018 Mercedes-Benz CLS550?
The most efficient configuration returns around 25 mpg (UK) combined, or 21 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 24 to 25 mpg.
How much does the 2018 Mercedes-Benz CLS550 cost to fuel per year?
The US EPA estimates about $3,900 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.
How much interior and luggage space does the 2018 Mercedes-Benz CLS550 have?
EPA measures interior passenger volume at 92 cubic feet (about 2,605 litres) and luggage volume at 11 cubic feet (about 311 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.