21 MPG combined isn’t going to shock the automotive world, but it’s perfectly acceptable for the 2018 Mercedes-Benz CLS550. This isn’t a car designed for hypermiling or setting fuel economy records. The CLS550 caters to a very specific buyer: one who prioritizes elegant design, strong power, and a luxurious driving experience over ultimate efficiency. They accept the fuel consumption as the price of admission to a certain level of automotive exclusivity, and the satisfying surge from the 4.7L V8.

City and highway performance

The EPA estimates of 18 MPG in the city and 26 MPG on the highway paint a fuller picture of the CLS550’s fuel usage. The city number reflects the inherent inefficiencies of stop-and-go driving, even with the nine-speed automatic transmission doing its best to keep the engine in its sweet spot.

The highway figure shows that the CLS550 truly shines on longer cruises, where the engine settles into a relaxed pace and the aerodynamic shape cuts through the air with minimal resistance. Driven with restraint on the open road, that 26 MPG is attainable and makes long road trips a genuinely pleasant experience. But let’s be honest, few CLS550 owners will spend much time driving slowly.

Annual fuel cost

The EPA estimates an annual fuel cost of $2,750 for the 2018 Mercedes-Benz CLS550. This figure is based on driving 15,000 miles per year, with approximately 55% of those miles driven in the city and 45% on the highway. It also assumes fuel prices based on the national average for premium gasoline when the EPA testing was performed. Individual fuel costs will, of course, vary based on driving habits, local fuel prices, and the type of driving done. But $2,750 is the benchmark figure that any prospective buyer should keep in mind when considering the cost of ownership.

Real-world expectations

While the EPA numbers provide a useful baseline, real-world fuel economy often deviates. CLS550 owners who enjoy the car’s performance capabilities – and let’s face it, the 402 horsepower V8 is tempting – will likely see figures closer to the combined rating than the highway ideal. Conversely, drivers who prioritize smooth, relaxed driving and stick to the open road might even slightly exceed the EPA’s highway estimate. It’s critical to remember that factors such as tire pressure, vehicle maintenance, and even the weather can all impact fuel economy. But generally, expect something in the high teens to low twenties in mixed driving.

How it compares

In the grand scheme of luxury sedans, the CLS550’s fuel economy is about average for its class. A 2018 BMW 650i Gran Coupe, for instance, equipped with its 4.4L V8, achieves an EPA-rated 17 MPG city, 25 MPG highway. The Audi A7 with its supercharged V6 posts 22 MPG combined. The differences are worth considering for buyers who might be cross-shopping these nameplates. Those searching for less gas in a Mercedes-Benz might consider a CLS450 model, but understand this entails accepting less power and potentially sacrificing the overall feel they want. You can browse all Mercedes Benz fuel economy data to find the most suitable model for your needs. Remember that checking CLS550 MPG across all years will show you what other options exist for this model.

Tips to maximize efficiency

Take it easy on the accelerator. The CLS550’s V8 offers effortless acceleration, but every hard launch and aggressive overtake takes a toll on fuel economy. Smooth, progressive acceleration will help you conserve fuel without sacrificing too much driving pleasure. The nine-speed automatic is designed to keep the engine in its most efficient range, so let it do its job.

Ensure your tires are properly inflated. Underinflated tires increase rolling resistance, forcing the engine to work harder and burning more fuel. Check your tire pressures regularly and inflate them to the pressure recommended on the doorjamb sticker. This small step can make a noticeable difference over time.

Minimize unnecessary weight. Carrying extra cargo in the trunk adds weight to the vehicle and reduces fuel efficiency. Remove any unnecessary items to lighten the load. The CLS550 is a substantial car already, so every little bit helps.

Plan your routes strategically. Avoid stop-and-go traffic whenever possible. Idling in traffic burns fuel without covering any distance. Look for routes with fewer traffic lights and more consistent speeds. Using the navigation system to find the most efficient route can also be beneficial.

Schedule regular maintenance. A well-maintained engine runs more efficiently. Follow the recommended maintenance schedule for your CLS550, including regular oil changes, air filter replacements, and spark plug inspections. A healthy engine is a fuel-efficient engine.