Maintaining the 2021 Mercedes-Benz GLE450 with its 3.0L inline-six turbocharged engine requires precision and high-quality lubricants. The GLE450 is a sophisticated luxury crossover that combines daily drivability with robust performance, thanks to its advanced powertrain and air suspension system. However, the demanding nature of turbocharging and direct injection places significant stress on engine components, making the choice of fluid critical for longevity. Using the correct viscosity and specifications ensures that the engine operates at peak efficiency, reduces carbon buildup on valves and injectors, and protects against the high thermal loads generated during spirited driving or towing. Proper lubrication also extends the service intervals, allowing owners to maximize the vehicle’s lifespan while maintaining the manufacturer’s recommended performance standards. For the ultimate in fuel system protection and carbon control, owners should consider using AMSOIL P.i. Performance Improver to restore injectors to 100% flow and AMSOIL Upper Cylinder Lubricant to lubricate the fuel system and prevent corrosion.
Recommended AMSOIL Products
- AMSOIL 5W-30 LS 100% Synthetic European Motor Oil – Engineered specifically for the unique demands of European gasoline, diesel, and hybrid vehicles, featuring a precise blend of synthetic base oils.
- AMSOIL 5W-40 MS 100% Synthetic European Motor Oil – A robust formulation designed to protect the turbocharged engine in all temperatures, ensuring low fuel consumption and high durability.
- AMSOIL 0W-20 LS 100% Synthetic European Motor Oil – An ultra-low viscosity option recommended by AMSOIL for achieving the lowest SAE viscosity class for optimal fuel economy.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix formulation that protects all cooling system metals, gaskets, and hoses while exceeding OEM requirements.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated formula requiring mixing with distilled water, offering protection up to 150,000 miles or 5 years.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides excellent ABS and traction-control responsiveness with stable viscosity over a wide temperature range.
The 2021 Mercedes-Benz GLE450 utilizes a complex cooling system designed to handle the thermal output of a twin-scroll turbocharger and a 48-volt mild hybrid system. The engine oil capacity for this specific configuration, including the filter, is 9 quarts. Owners must ensure they refill to the correct level and verify the oil gauge after refilling, as overfilling or underfilling can lead to significant performance issues or seal failures. The engine oil must meet specific European standards to ensure compatibility with the turbocharger bearings and the delicate emission control systems. While the recommended grades include 0W-40 and 5W-40 for all temperatures, the selection of an ultra-low viscosity oil like 0W-20 can be beneficial for achieving the lowest possible fuel consumption, provided it is compatible with the specific engine code 256.930 2 Turbo. For extreme cold conditions or storage, AMSOIL Engine Fogging Oil offers a highly effective rust preventive to protect internal components.
Cooling System and Fluid Maintenance
The cooling system in the GLE450 is vital for managing the heat generated by the high-compression turbocharged engine. With a capacity of 20 quarts, the system requires a significant volume of AMSOIL Passenger Car & Light Truck Antifreeze & Coolant to function correctly. Using a high-quality antifreeze is essential to prevent corrosion, freeze-up, and boiling over. The AMSOIL Passenger Car & Light Truck Antifreeze is formulated to be phosphate-free and silicate-free, making it compatible with the aluminum components and rubber hoses found in this luxury SUV. For owners who prefer to mix their own solutions or have access to concentrated fluids, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers a robust alternative that provides extended protection against rust and erosion in heavy-duty applications.
AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid and Safety Systems
Modern safety systems in the GLE450, including electronic stability control and advanced braking assist, rely heavily on the condition of the brake fluid. The vehicle specifies the use of DOT 4 plus fluid, which meets the MB Sheet 331.0 standard. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is an ideal replacement, offering a higher dry and wet boiling point than standard DOT 4 fluids. This synthetic formulation resists moisture absorption better than conventional glycol-based fluids, maintaining pedal feel and responsiveness even after extensive use. Regular changes of brake fluid are crucial to prevent corrosion in the calipers and the ABS module, ensuring the safety systems operate reliably in wet or extreme conditions. To maintain the integrity of rubber seals and prevent drying, AMSOIL Silicone Spray can be used to protect surfaces without damaging rubber components.
In addition to the primary lubricants, maintaining the GLE450’s fuel system is essential for performance. Direct injection engines are prone to carbon buildup on intake valves, which can affect power and fuel economy. Adding AMSOIL P.i. Performance Improver to the fuel tank can help restore fuel injectors to 100% flow rate, potentially restoring up to 14% of horsepower and improving overall fuel economy. For seasonal storage, owners can utilize AMSOIL Gasoline Stabilizer to keep fuel fresh for up to 12 months, preventing varnish and gum buildup that can clog injectors and fuel lines. These additives work synergistically with the synthetic motor oils to ensure the entire powertrain remains in top condition. For general cleaning needs, AMSOIL Heavy-Duty Degreaser effectively dissolves oil and grime, while AMSOIL Brake and Parts Cleaner removes contaminants from brake components without leaving residue.
About the Vehicle
The 2021 Mercedes-Benz GLE450 represents a significant step in the evolution of the luxury crossover segment. Based on the robust Mercedes-Benz M-class platform, the GLE is known for its blend of off-road capability and on-road refinement. The 2021 model year features the updated MBUX infotainment system and a refined exterior design that commands attention on the highway and in city traffic. Under the hood lies the OM656 3.0-liter inline-six engine, which is not just a naturally aspirated unit but a twin-scroll turbocharger setup paired with a 48-volt EQ Boost mild hybrid system.
This powertrain delivers approximately 362 horsepower and 369 lb-ft of torque, providing brisk acceleration and effortless passing power. The 48-volt system assists the turbocharger to eliminate lag and provides a smooth start-stop function, contributing to the vehicle’s exceptional ride quality. The GLE450 comes standard with the 4MATIC all-wheel-drive system, which dynamically distributes power between the front and rear axles to optimize traction. This makes the vehicle highly capable in adverse weather conditions without sacrificing the agile handling characteristics expected of a sports-luxury SUV.
Despite its sophistication, the GLE450 is not without common issues that owners should be aware of. One frequent concern is the potential for high-pressure fuel pump failures, a known issue in the M256 engine family that can lead to stalling or difficulty starting. Another common problem involves the air suspension system, where air struts may develop leaks over time, leading to the vehicle sitting unevenly or the suspension failing to level the vehicle. Carbon buildup on the intake valves is a third prevalent issue due to the direct injection nature of the engine, which can degrade performance if not managed with quality fuel additives. Additionally, owners have reported issues with the battery monitoring sensor, which can incorrectly trigger a “battery replacement required” message even when the battery is healthy, leading to unnecessary expenses.
Using high-performance synthetic lubricants can help mitigate the effects of these common problems. The superior thermal stability of AMSOIL 5W-30 LS 100% Synthetic European Motor Oil and AMSOIL 5W-40 MS 100% Synthetic European Motor Oil helps protect the high-pressure fuel pump and turbocharger bearings from the extreme heat generated during operation. The advanced additive packages in AMSOIL P.i. Performance Improver help minimize carbon deposits on intake valves, addressing the root cause of power loss in direct injection engines. For the air suspension and other rubber components, AMSOIL Silicone Spray and AMSOIL Heavy-Duty Metal Protector can help prevent drying, cracking, and corrosion caused by heat and exposure to the elements, extending the life of seals and bushings. For detailed vehicle care, AMSOIL High-Foam Car Shampoo is gentle on coatings, while AMSOIL Exterior Ceramic Spray provides rapid water shedding and UV protection. AMSOIL Interior Detailer – Light Lemon or the AMSOIL Interior Detailer – Scent Free can trap odors and offer UV protection for the cabin, and AMSOIL Glass Cleaner ensures clear visibility. By prioritizing these high-quality fluids and care products, owners can enjoy a smoother, more reliable driving experience and reduce the likelihood of costly repairs associated with these known vulnerabilities. For exterior mud and dirt protection, AMSOIL Mudslinger provides a non-stick layer of armor, and for general cleaning, AMSOIL Power Foam cleans deposits from the fuel system, while AMSOIL Engine Degreaser tackles tough grime.
The GLE450 is a vehicle designed for those who demand the best in safety, comfort, and performance. Whether navigating icy mountain passes or cruising on the highway, the right maintenance regimen ensures that this luxury SUV continues to deliver the premium experience it was built to provide. From the precision-engineered engine to the sophisticated suspension, every component benefits from the protection offered by top-tier synthetic lubricants.