Maintaining the 2012 Mercedes-Benz GL450 with a 4.7L V8 engine requires a rigorous approach to lubrication and fluid management. This vehicle, equipped with engine code 273.923-9, is engineered for high performance and substantial towing capacity, placing significant thermal and mechanical stress on internal components. Using incorrect or degraded fluids can lead to premature wear, reduced fuel efficiency, and costly transmission repairs. Owners of this German import understand that factory specifications are a baseline; they expect superior protection to handle extreme temperatures, heavy loads, and extended driving intervals. Proper lubrication ensures that the engine, transmission, and ancillary systems operate with precision and longevity.
Recommended AMSOIL Products
- AMSOIL 5W-40 FS 100% Synthetic European Motor Oil – A premium synthetic specifically formulated for European vehicles, providing precise protection against high heat and thermal breakdown in the 4.7L V8.
- AMSOIL 0W-40 FS 100% Synthetic European Motor Oil – Offers superior cold-weather flow and maximum heat protection, ideal for extreme temperature variations and high-performance driving.
- AMSOIL Oil Filter – Provides 99% filtration efficiency at 20 microns, ensuring that critical engine components are protected from wear-causing contaminants.
- WIX Oil Filter – Features premium media that offers improvements over original equipment manufacturer (OEM)-branded filters for enhanced flow and filtration.
- MANN-FILTERS Oil Filter – Delivers top-tier filtration performance trusted by many European vehicle owners for reliable engine protection.
- MANN-FILTERS Air Filters – Helps the engine breathe efficiently, protecting combustion chambers from dust and debris while maintaining optimal airflow.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix formulation that protects all cooling system metals, gaskets, and hoses, preventing corrosion and overheating.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated, phosphate- and silicate-free option that delivers extended protection for up to 150,000 miles or 5 years.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Designed to withstand the rigors of heavy towing and elevated temperatures while remaining fluid in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A cost-effective, full synthetic alternative that protects against wear and maintains shift quality.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides stable viscosity over a wide temperature range with excellent responsiveness for ABS and traction-control systems.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Reduces friction and helps seals remain soft to prevent leaks, ensuring quiet operation and long fluid life.
Engine Oil Specifications and Selection
The heart of your 2012 Mercedes-Benz GL450 is the 4.7L V8 engine. For this specific application, the correct oil viscosity and certification are paramount to ensure optimal performance. The manufacturer recommends oil grades of 0W-30 or 0W-40 for all temperatures, and 5W-30 or 5W-40 for temperatures above -25°C. To fill the system correctly, you will require 9.5 quarts of lubricant when changing the oil filter. It is critical to check the oil level after the refill is complete to ensure proper coverage.
AMSOIL 5W-40 FS 100% Synthetic European Motor Oil is a premier choice for this engine. It is designed specifically for the unique demands of gasoline, diesel, and hybrid European vehicles. The formula features a precise blend of synthetic base oils and premium additives that resist thermal breakdown and shear, which are common issues in high-stress V8 engines. Similarly, AMSOIL 0W-40 FS 100% Synthetic European Motor Oil provides an excellent alternative for those seeking maximum cold-start protection without sacrificing high-temperature stability. Both oils meet or exceed the rigorous requirements of European standards, offering a level of protection that extends beyond standard factory recommendations.
Lubricant Capabilities and Maintenance
When servicing the engine, pairing your oil with a high-quality filter is essential for complete protection. The AMSOIL Oil Filter (EA15K39-EA) is engineered to provide filtering efficiency of 99 percent at 20 microns. This high level of filtration removes wear-causing contaminants more effectively than many competitors, keeping engine parts properly lubricated and reducing overall wear. The filter also offers greater capacity for small particles, helping to extend the service life of the lubricant. Alternatively, WIX Oil Filter (57078-EA) and MANN-FILTERS Oil Filter (HU7185X-EA) are excellent choices that feature premium media, offering improvements over original equipment manufacturer (OEM)-branded filters.
Beyond the engine, the cooling system of the GL450 requires attention. The vehicle has a total capacity of 12.7 quarts of coolant. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a convenient 50/50 pre-mix formulation that protects all cooling system metals, gaskets, and hoses. It is phosphate-, nitrate-, silicate-, borate-, and amine-free, which ensures compatibility with the vehicle’s metal alloys. For owners who prefer to mix their own coolant or require a concentrated option, AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers protection up to 150,000 miles or 5 years. Both options greatly surpass standards for metallic corrosion and erosion, keeping the engine at optimal operating temperatures.
Transmission and Drivetrain Protection
The 2012 GL450 is equipped with a 7-speed automatic transmission (722.9) that demands specific fluid characteristics to function smoothly. Whether the vehicle has the reduced-friction code A89 or not, the capacity for a total fill is 9.5 quarts. Using the correct fluid is vital for preventing wear, sludge, and temperature-related problems. AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is designed to withstand the rigors of heavy towing, elevated temperatures, and challenging terrain. It remains fluid in sub-zero temperatures and provides reserve protection during heavy use and abuse. For those seeking a highly effective, fuel-efficient synthetic option, AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers robust protection against wear and maintains shift quality.
For the transfer case and differential, the requirements are equally specific. The double-speed transfer case requires 3.2 pints, while the single-speed version needs 1.1 pints. The front differential capacity is 2.3 pints. While specific gear lubricants were noted, the transmission fluids mentioned above are also recommended for these components in certain configurations to ensure consistent performance. Ensuring these areas are properly lubricated helps maintain the vehicle’s four-wheel-drive capabilities and transfer efficiency, especially when towing heavy loads or navigating off-road conditions.
Fluids for Safety and Performance
AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is an ideal choice, offering excellent ABS and traction-control responsiveness. Its stable viscosity over a wide temperature range ensures consistent pedal feel, regardless of the driving conditions. For the power steering system, AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is recommended. This fluid reduces friction, helps seals remain soft to prevent leaks, and offers strong anti-wear protection, ensuring quiet operation and long fluid life.
Seasonal maintenance and storage should not be overlooked. If the vehicle is stored for extended periods, AMSOIL Gasoline Stabilizer can keep the fuel fresh for up to 12 months, protecting against varnish and gum buildup. Additionally, AMSOIL Engine Fogging Oil is a highly effective rust preventive designed to protect internal engine components during storage or long periods of inactivity. For year-round performance, AMSOIL P.i. Performance Improver Gasoline Additive can help restore up to 14% horsepower and improve fuel economy by cleaning fuel injectors and preventing carbon buildup.
About the Vehicle
The 2012 Mercedes-Benz GL450 stands as a testament to German engineering, blending the rugged capabilities of a traditional SUV with the luxury and refinement expected from the Mercedes-Benz brand. Part of the G-Class lineage in SUV form, the GL-Class, which includes the GL450 model, was designed to offer three rows of seating and a robust towing capacity, making it a versatile choice for families and adventurers alike. Under the hood, the 4.7-liter V8 engine delivers a substantial amount of power, allowing the heavy vehicle to accelerate with surprising agility and pull significant loads, such as boats or campers, with ease.
This vehicle was marketed as a premium full-size luxury SUV, competing in a segment defined by high-end competitors like the Cadillac Escalade and the Audi Q7. The GL450’s platform is built on a ladder-frame design, which provides durability and off-road capability that unibody competitors often lack. Owners appreciate the combination of a comfortable, quiet interior with a commanding driving position and advanced safety features. The 4.7L V8, produced by Mercedes-AMG, is known for its smooth power delivery and reliability when maintained correctly. The vehicle’s reputation is built on its ability to serve as a daily driver while still being capable of handling rough terrain and long-distance towing trips. Its market position is unique, offering a spacious, three-row interior without sacrificing the ruggedness associated with the brand’s heritage. This makes the GL450 a favorite among those who need practicality but refuse to compromise on performance or prestige.