25 MPG combined won’t win any hypermiling awards, but it’s a respectable figure for the 2021 Mercedes-Benz CLS450 4matic. This car prioritizes sleek design, effortless performance, and advanced technology over fuel savings. The CLS450 buyer isn’t solely focused on minimizing trips to the gas station; they’re seeking a stylish and comfortable four-door coupe with strong power and all-weather capability. This MPG balances those desires with a manageable fuel bill.

City and highway performance

The EPA estimates the CLS450 at 22 MPG in the city and 29 MPG on the highway. The city figure reflects stop-and-go driving conditions common in urban environments. The car’s weight and the inefficiencies of combustion engines in traffic affect this number. However, the 29 MPG highway rating shows the smooth and efficient 3.0L inline-six engine’s benefits. It also shows the benefits of its 9-speed automatic transmission, specifically tuned for relaxed cruising at higher speeds. This transmission allows the engine to operate at lower RPMs on the open road, reducing fuel consumption. The 4matic all-wheel-drive system adds weight, slightly impacting fuel economy versus a rear-wheel-drive variant, but provides enhanced traction and stability, a priority for many buyers in colder climates. For all Mercedes Benz fuel economy data, browse here.

Annual fuel cost

The EPA estimates the annual fuel cost for the 2021 Mercedes-Benz CLS450 4matic at $2,300. This is based on driving 15,000 miles per year and using national average fuel prices for premium unleaded gasoline, the recommended fuel type for optimal performance. Your actual fuel costs may vary depending on your driving habits, local fuel prices, and the amount of miles you drive annually. However, the $2,300 serves as a useful benchmark when comparing the CLS450’s running costs to other vehicles in its class.

Real-world expectations

While the EPA estimates provide a standardized baseline, real-world fuel economy can differ. The CLS450’s fuel efficiency depends on driving style. A driver who frequently uses the engine’s reliable power output can expect numbers closer to the low end of the EPA range, maybe even slightly below. A driver with a gentler touch, who anticipates traffic flow and avoids aggressive acceleration, may see results closer to, or even slightly exceeding, the EPA estimates, especially on long highway trips. Factors like tire pressure, vehicle maintenance, and the use of accessories like air conditioning can also influence fuel consumption.

Owners should be aware that modern engine management systems can react differently to varying grades of fuel, with premium unleaded generally providing better performance and improved fuel economy.

How it compares

Several competitors emerge when cross-shopping the CLS450. The Audi A7, with its 3.0-liter TFSI engine, achieves an EPA-estimated 24 MPG combined. The BMW 840i Gran Coupe, another stylish four-door coupe, posts figures around 25 MPG combined, similar to the CLS450. Even the Porsche Panamera, a performance-oriented sedan, can achieve around 21 MPG combined in its base trim. While these vehicles may offer slightly better or worse fuel economy, the differences are often negligible for the target customer. The decision often comes down to styling preferences, brand loyalty, and other factors beyond mere MPG. The driving experience, interior design, and available technology all play a significant role in the purchasing decision. Compare these estimates across all years of CLS450 MPG across all years.

Tips to maximize efficiency

The CLS450’s 3.0L inline-six engine is equipped with an “ECO” drive mode. Use this mode during everyday driving to prioritize fuel efficiency. It adjusts the throttle response and transmission shift points to encourage a more relaxed and economical driving style. Consider using “Comfort” mode as a default, only switching to “Sport” or “Sport+” when you want to unleash the car’s performance.

Ensure your tires are properly inflated to the recommended pressure, which can be found on the driver’s side doorjamb. Underinflated tires increase rolling resistance, which negatively impacts fuel economy. Regularly check and adjust tire pressure, especially during seasonal temperature changes.

Avoid unnecessary idling. Modern engines are more efficient when turned off and restarted, even for short periods. If you’re stopped for more than a minute or two, it’s generally more fuel-efficient to turn off the engine. The CLS450 may come equipped with a start/stop system that automates this process.

Minimize use of accessories like air conditioning, especially on shorter trips. The A/C compressor places a load on the engine, increasing fuel consumption. When weather permits, open the windows or using the car’s ventilation system instead.

Plan your trips efficiently to avoid congested routes and minimize stop-and-go driving. Using a navigation system with real-time traffic updates can help you identify and avoid traffic bottlenecks, reducing fuel consumption and saving you time.