Improve CLS Class Fuel Consumption Efficiency

Discover how the Mercedes-Benz CLS Class balances exhilarating performance with impressive fuel efficiency, offering drivers a luxurious and surprisingly economical driving experience.

Driving a Mercedes-Benz CLS Class is often associated with thrilling power and opulent comfort. But a common question for many owners and prospective buyers is: “What about the fuel consumption?” It’s a natural concern, especially with such a potent machine. The good news is that Mercedes-Benz engineers have worked hard to make the CLS Class remarkably efficient, especially considering its performance capabilities. This guide will break down what influences the CLS’s fuel economy, explore typical figures, and offer tips to help you maximize every gallon. We’ll ensure you understand exactly what to expect from your CLS Class’s fuel consumption.

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Understanding CLS Class Fuel Consumption

When we talk about fuel consumption for a vehicle like the Mercedes-Benz CLS Class, it’s a blend of engineering, driving habits, and the specific model you choose. The CLS is designed to deliver a dynamic driving experience, often featuring powerful engines that can make fuel economy seem like a secondary consideration. However, modern automotive technology plays a significant role in bridging the gap between performance and efficiency.

Understanding the factors that influence your CLS Class’s Miles Per Gallon (MPG) or Liters per 100 Kilometers (L/100km) is the first step to managing it. These factors range from the engine size and type to how you grip the steering wheel and the conditions under which you drive.

Key Factors Influencing CLS Fuel Economy

Several elements contribute to the fuel consumption figures you’ll see on your CLS Class. By understanding these, you can better interpret the numbers and even influence them.

Engine Size and Type: Larger engines, especially those with more cylinders (V6, V8), naturally require more fuel than smaller ones. However, advancements like turbocharging and direct injection can significantly improve efficiency even in larger displacement engines. The CLS has historically offered a range of engines, from potent inline-sixes to powerful V8s.
Drivetrain: Whether your CLS is rear-wheel drive (RWD) or all-wheel drive (4MATIC in Mercedes-Benz terminology) can impact fuel economy. 4MATIC systems add a bit of weight and mechanical drag, which can lead to slightly higher fuel consumption compared to their RWD counterparts.
Transmission: The type and sophistication of the transmission are crucial. Modern automatic transmissions, like Mercedes-Benz’s 9G-TRONIC, are designed with numerous gear ratios to keep the engine operating within its most efficient RPM range for longer periods.
Driving Style: This is arguably the biggest variable you can control. Aggressive acceleration, sudden braking, and high-speed driving will dramatically increase fuel consumption. Smooth, steady driving, anticipating traffic, and utilizing cruise control on highways are far more economical.
Vehicle Weight: The CLS is a luxury vehicle, meaning it comes with features that add weight. More weight requires more energy (and thus, fuel) to accelerate and maintain speed.
Tire Pressure: Underinflated tires create more rolling resistance, forcing the engine to work harder and consume more fuel. Regularly checking and maintaining correct tire pressure is a simple yet effective way to improve MPG. You can find the recommended tire pressures on a sticker on the driver’s side doorjamb or in your owner’s manual.
Aerodynamics: While the CLS boasts a sleek, coupe-like silhouette designed for aerodynamic efficiency, factors like open windows at high speeds or exterior modifications can hinder airflow and increase drag, thus impacting fuel economy.
Maintenance: A well-maintained engine runs more efficiently. Regular oil changes, clean air filters, and properly functioning spark plugs all contribute to better fuel economy. A clogged air filter, for instance, can restrict airflow to the engine, making it less efficient.

CLS Class Fuel Consumption Figures by Model

The fuel consumption of a CLS Class can vary significantly depending on the specific generation, model designation, engine, and drivetrain. Mercedes-Benz provides official MPG estimates, which are often determined under standardized testing conditions. However, real-world driving can differ. Below is a general overview of typical fuel consumption figures for recent CLS models. These figures are approximate and can be affected by the factors mentioned above.

For the most accurate and up-to-date figures for a specific model year and trim, it’s always best to consult the official EPA’s FuelEconomy.gov website or your vehicle’s owner’s manual.

CLS Model (Example)	Engine Type	Drivetrain	City MPG (Approx.)	Highway MPG (Approx.)	Combined MPG (Approx.)
CLS 450 (Recent Generations)	3.0L Turbo I6 with Mild Hybrid	RWD / 4MATIC	22-25	30-33	25-28
CLS 53 AMG (Recent Generations)	3.0L Turbo I6 EQ Boost	4MATIC+	18-21	26-28	21-24
CLS 63 AMG (Older V8 Models)	4.0L Biturbo V8	RWD / 4MATIC	14-16	22-24	17-19

The Role of Mild Hybrid Technology (EQ Boost)

Many newer CLS models, particularly the CLS 450 and CLS 53 models, feature Mercedes-Benz’s EQ Boost mild-hybrid system. This technology is a significant contributor to improved fuel efficiency in these potent luxury sedans.

EQ Boost uses an integrated starter-generator (ISG) that is belt-driven and sits between the engine and transmission. This system provides several benefits:

Electric Assistance: It can deliver a temporary boost of electric power to the engine during acceleration, reducing the load on the combustion engine and thus improving fuel economy.
Regenerative Braking: During deceleration and braking, the ISG acts as a generator, capturing energy that would otherwise be lost as heat and storing it in a small onboard battery. This energy can then be used to power the car’s electrical systems or provide that performance boost.
Smoother Start/Stop: The system allows for smoother and more efficient engine start/stop operations, reducing fuel wasted during idling.
Enhanced Driving Dynamics: Beyond efficiency, the electric boost can improve throttle response and provide a more seamless power delivery.

The addition of EQ Boost means that even powerful CLS variants can achieve MPG figures that were once unthinkable for their class and performance level.

Understanding AMG CLS Fuel Consumption

For those who opt for the high-performance AMG versions of the CLS Class, such as the CLS 63 or CLS 53, fuel consumption will naturally be higher due to the more powerful engines, sport-tuned transmissions, and the emphasis on maximum performance. These vehicles are engineered for exhilarating acceleration and dynamic handling, which inherently consumes more fuel.

While figures for AMG models are lower than their non-AMG counterparts, Mercedes-AMG engineers still strive for the best possible efficiency within the performance envelope. For example, AMG models often feature advanced engine management systems, larger turbochargers for power, and sophisticated exhaust systems. The CLS 53 AMG, with its inline-six and EQ Boost, offers a compelling blend of AMG performance and improved efficiency compared to older V8 AMG CLS models.

If performance is your priority and you’re considering an AMG CLS, it’s wise to budget for higher fuel costs. However, many enthusiasts find the thrilling driving experience to be well worth the premium at the pump.

Maximizing Your CLS Class Fuel Efficiency

Even with its efficient engineering, you can make a tangible difference in your CLS Class’s fuel consumption with conscious driving habits and simple maintenance. Here’s how to get the most out of every drop of fuel:

Driving Techniques for Better MPG

Your driving style has the most significant impact on real-world fuel economy. Adopting a smoother, more predictive approach can lead to substantial savings over time.

Smooth Acceleration and Braking: Gradually apply the accelerator instead of flooring it. Anticipate stops and traffic lights, easing off the gas early rather than braking hard at the last moment. This not only saves fuel but also reduces wear on your brakes.
Maintain a Steady Speed: On highways, use your cruise control feature to maintain a consistent speed. Fluctuations in speed require the engine to work harder, consuming more fuel.
Observe Speed Limits: Fuel efficiency generally decreases significantly above 50-60 mph. Driving at or slightly below the speed limit on highways can lead to noticeable fuel savings.
Minimize Idling: If you’re going to be stopped for more than 30 seconds (e.g., waiting for someone or at a long train crossing), it’s often more fuel-efficient to turn off the engine and restart it when you’re ready to go. Newer CLS models with advanced start/stop systems handle this automatically and efficiently.
Plan Your Routes: Combine errands into a single trip to minimize cold starts. A cold engine is less efficient than a warm one. Also, consider routes that have fewer stops and starts.

Vehicle Maintenance for Optimal Efficiency

Regular and proper maintenance ensures your CLS Class is running at its peak performance and efficiency. Neglected maintenance can lead to a noticeable increase in fuel consumption.

Regular Oil Changes: Use the manufacturer-recommended grade of engine oil. Clean oil lubricates the engine efficiently, reducing friction and improving fuel economy. Check your owner’s manual for the correct oil type and viscosity.
Air Filter Replacement: A dirty air filter restricts airflow to the engine, making it work harder and consume more fuel. Replace your air filter according to the manufacturer’s recommended schedule, or sooner if you drive in dusty conditions.
Tire Pressure Maintenance: As mentioned, underinflated tires increase rolling resistance. Check your tire pressure at least once a month when the tires are cold. The recommended pressure is usually found on a sticker in the driver’s side doorjamb or in the owner’s manual. For proper tire information, consult Tire Rack’s guide on tire pressure, a reputable source for automotive tire information.
Wheel Alignment: Improper wheel alignment can cause tires to drag, increasing resistance and fuel consumption. Have your alignment checked if you notice uneven tire wear or if your car pulls to one side.
Spark Plug Check: Worn or fouled spark plugs can lead to incomplete combustion, wasting fuel and reducing engine power. Ensure they are inspected and replaced as part of your regular maintenance schedule.

Understanding and Using Driving Modes

Many Mercedes-Benz vehicles, including the CLS Class, offer selectable driving modes, often accessible via a dial or button on the center console. These modes allow you to tailor the car’s performance and efficiency characteristics:

“ECO” Mode: This mode is designed to maximize fuel efficiency. It typically adjusts the throttle response to be less sensitive, alters transmission shift points to keep the engine at lower RPMs, and may even optimize climate control settings.
“COMFORT” Mode: This is the standard mode, offering a balance between smooth ride quality, responsive acceleration, and reasonable fuel economy.
“SPORT” or “SPORT+” Modes: These modes prioritize performance. They sharpen throttle response, hold gears longer for higher RPMs, and may firm up the suspension. While exhilarating, they will lead to higher fuel consumption.

For everyday driving where fuel efficiency is a priority, using the “ECO” or “COMFORT” modes will yield better MPG. The “Sport” modes are best reserved for when you truly want to experience the CLS’s performance and are willing to accept the increased fuel usage.

Frequently Asked Questions (FAQ) on CLS Class Fuel Consumption

Q1: Is CLS Class fuel economy good for a luxury sedan?

A: Yes, for its class and performance capabilities, the CLS Class generally offers competitive fuel economy, especially with newer models equipped with mild-hybrid technology (EQ Boost) and efficient transmissions like the 9G-TRONIC. While not as economical as a compact car, its MPG figures are often surprisingly good for a vehicle offering such power and luxury.

Q2: How much does 4MATIC affect CLS mileage?

A: Mercedes-Benz’s 4MATIC all-wheel-drive system typically results in a slight decrease in fuel economy compared to rear-wheel-drive models. This is due to the added weight and mechanical drag of the extra components directing power to all four wheels. The difference is usually a few MPG, often more noticeable in city driving than on the highway.

CLS Class Fuel Consumption: Effortless Power