The 2018 Mercedes-Benz CLS550 4matic achieves 20 MPG combined, a figure that likely doesn’t dissuade its target demographic. This isn’t a car bought for frugal errands; it’s a strong blend of luxury, style, and effortless power. The CLS550’s V8 rumble and sleek silhouette are design statements, and fuel economy concerns often take a backseat to the experience it delivers. Buyers of this model prioritize performance and prestige over squeezing every last mile from a gallon.

City and highway performance

The 2018 CLS550’s EPA ratings break down to 17 MPG in the city and 25 MPG on the highway. The city figure reflects the demands of stop-and-go traffic, where the 4.7L V8’s substantial power requires more fuel to get moving. The highway rating paints a slightly rosier picture, aided by the smooth-shifting 9-speed automatic transmission. At cruising speeds, the engine settles into a more relaxed state, allowing for better efficiency. However, the CLS550’s weight and all-wheel-drive system inevitably impact those highway numbers, preventing it from achieving the economy of lighter, front-wheel-drive sedans.

Annual fuel cost

According to the EPA, the estimated annual fuel cost for the 2018 Mercedes-Benz CLS550 4matic is $2,900. This figure is based on driving 15,000 miles per year, with a mix of city and highway driving, and using the EPA’s estimate of the national average fuel price. It’s useful for comparison against other vehicles, and your actual fuel costs may vary depending on your driving habits, fuel prices in your area, and the type of fuel you use. Premium fuel is recommended for optimal performance, which usually increases fuel costs further.

Real-world expectations

While the EPA provides a standardized measure, real-world fuel economy is often influenced by factors beyond the test cycle. The CLS550’s twin-turbocharged V8 begs to be unleashed, and enthusiastic driving will undoubtedly lower fuel economy. Similarly, extended idling in traffic or frequent short trips can negatively impact MPG. Owners who prioritize a light foot and primarily use the car for longer highway journeys are more likely to achieve numbers closer to, or even slightly above, the EPA estimates. Take note of other year models like the CLS550 MPG across all years to get an idea of how the numbers have changed.

How it compares

In the realm of luxury performance sedans, the 2018 CLS550’s fuel economy sits somewhere in the middle. A direct competitor is the BMW 550i xDrive, which offers similar performance and all-wheel drive, but achieves a slightly better 20 MPG city and 29 MPG highway in some model years. The Audi A7 with the supercharged V6 engine, while offering a different driving experience, lands in the same ballpark at around 22 MPG combined. Moving up the Mercedes-Benz ladder, you’ll find that the AMG variants of the CLS prioritize performance even further, resulting in fuel economy figures that dip lower, sometimes into the mid-teens for city driving. Those considering the CLS550 often accept the fuel consumption as a tradeoff for its unique blend of luxury, power, and distinctive styling, but do cross-shop against alternatives to find the best fit for their needs.

Tips to maximize efficiency

The 2018 CLS550 4matic isn’t designed to be a fuel-sipper, but adopting certain driving habits can help improve its efficiency. Avoid aggressive acceleration and heavy braking, which put extra strain on the engine and consume more fuel. Anticipate traffic flow and maintain a steady speed whenever possible.

Use the CLS550’s driving modes. Selecting “Comfort” mode will dampen throttle response and encourage the transmission to upshift sooner, promoting fuel efficiency. Reserve “Sport” and “Sport+” modes for spirited driving where performance is the priority.

Ensure that the tire pressure is properly inflated. Underinflated tires increase rolling resistance, which reduces fuel economy. Check the tire pressure regularly and inflate to the recommended levels found on the driver’s side doorjamb.

Reduce unnecessary weight in the vehicle. Extra cargo adds load and increases fuel consumption. Remove any items that aren’t needed for your trips to lighten the load and improve efficiency. See all Mercedes Benz fuel economy data for other fuel saving alternatives from the marque itself.

Schedule regular maintenance for your CLS550. A well-maintained engine runs more efficiently. Ensure that oil changes, air filter replacements, and other routine services are performed on time to keep the engine operating at its best.