Maintaining the 2009 Mercedes-Benz GL320, a robust luxury SUV, requires fluids that meet the rigorous demands of its 3.0L turbo-diesel engine. Proper lubrication is essential for preserving performance, ensuring smooth operation, and extending the vehicle’s lifespan. Using high-quality synthetic fluids helps protect critical components from wear, corrosion, and thermal breakdown, which is particularly important for this model given its engineering standards. Whether you are navigating city traffic or towing heavy loads on the highway, the correct lubricants provide the necessary stability and protection for every drive.
Recommended AMSOIL Products
- AMSOIL 0W-30 MS 100% Synthetic European Motor Oil – A premium synthetic fluid designed for the precise demands of European gasoline, diesel, and hybrid engines, offering exceptional protection against turbocharger stress and extending drain intervals.
- MANN-FILTERS Oil Filter – A high-efficiency filtration component that provides superior media quality to capture contaminants, ensuring cleaner oil circulation and enhanced engine protection compared to standard OEM filters.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – An advanced synthetic fluid engineered to withstand heavy towing, elevated temperatures, and challenging terrain while maintaining fluid performance in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A cost-effective synthetic option that meets original equipment manufacturer requirements, offering reliable wear protection for the transmission system.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – A high-performance synthetic fluid that delivers excellent responsiveness for ABS and traction control systems while maintaining stable viscosity across a wide temperature range.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – A versatile synthetic fluid formulated to reduce friction, keep seals soft to prevent leaks, and offer strong anti-wear protection for long fluid life.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A pre-mixed poly-organic acid coolant that protects cooling system metals, gaskets, and hoses, providing up to 150,000 miles or 5 years of protection.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated, eco-friendly coolant solution that requires mixing with water, offering extended protection up to 150,000 miles in passenger cars and light trucks.
Why Proper Fluid Selection Matters for the GL320
The 2009 Mercedes-Benz GL320 is equipped with a sophisticated 3.0L inline-six diesel turbo engine (Engine Code 642.820 F). This powertrain is engineered for high torque and efficiency, but it also operates under significant thermal and mechanical stress. The use of substandard oils or coolants can lead to premature wear, clogged filters, and reduced fuel economy. Because this vehicle was manufactured to European standards, it requires lubricants that exceed standard industry specifications. AMSOIL synthetic motor oils are rigorously tested to meet and exceed these demanding OEM requirements, ensuring that the engine, transmission, and auxiliary systems operate smoothly regardless of driving conditions.
One of the most critical aspects of maintaining this vehicle is adhering to the correct fluid capacities and specifications. For instance, the engine oil system holds approximately 9.0 quarts, including the filter. If the vehicle is equipped with an oil cooler, additional oil may be needed if the cooler is drained during service. After refilling, it is crucial to allow the engine to sit for about five minutes before checking the oil level to ensure an accurate reading. The oil drain plug should be torqued to 22 ft/lbs to prevent leaks while avoiding damage to the plug or the engine block.
Similarly, the cooling system requires precise fluid management. With a total capacity of 10 quarts, the GL320 benefits from antifreeze formulations that offer enhanced corrosion protection. The recommended fluids utilize poly-organic acid technology, which is free of phosphates, nitrates, and silicates, making them compatible with all cooling system components and other coolant colors. This ensures long-term protection for the radiator, water pump, and engine block against rust and scale buildup.
Transmission and Drivetrain Lubrication
The transmission in the GL320 is a vital component that demands specific attention. The automatic transmission requires a fluid that can handle the rigors of shifting, towing, and sustained highway driving. AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is designed for maximum performance, offering reserve protection during heavy use and abuse while remaining fluid in sub-zero temperatures. Alternatively, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid provides reliable wear protection that meets original equipment standards.
Both fluid types are designed for a total fill of 9.5 quarts for the 7-speed 722.9 transmission. It is important to note that capacity can vary slightly based on whether the vehicle has specific data card codes such as A89 for reduced friction. Using the correct fluid ensures that the transmission shifts smoothly and efficiently, preventing slippage and heat-related degradation. The drivetrain, including the transfer case, also benefits from synthetic lubrication. For double-speed transfer cases, 3.2 pints are required, while single-speed units need 1.1 pints. Front differentials typically require 2.3 pints. Utilizing synthetic lubricants in these areas reduces friction and wear, extending the life of the transfer case and differentials significantly.
Braking and Steering System Fluids
Safety is paramount when it comes to a vehicle of this size and weight. The braking system of the GL320 requires a fluid that maintains its properties under high temperatures and pressure. The recommended AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is formulated to provide excellent responsiveness for anti-lock braking systems and traction control. It maintains a stable viscosity over a wide temperature range, ensuring consistent brake pedal feel and stopping power. This fluid meets the requirements for HBH applications and is suitable for vehicles needing DOT 4 plus specifications.
AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is another essential fluid that is often overlooked. The GL320’s power steering system operates under pressure, and a fluid that resists heat and oxidation is crucial. The AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid reduces friction and helps seals remain soft, which prevents leaks and squeaking noises. It offers strong anti-wear protection and excellent high- and low-temperature performance, contributing to a quiet and responsive steering system.
Fuel Additives and Maintenance Products
For the 3.0L diesel engine, maintaining fuel system cleanliness is key to optimal performance. AMSOIL Diesel Injector Clean Fuel Additive cleans deposits and improves lubricity, while the AMSOIL Diesel Cetane Boost Fuel Additive increases cetane levels for better startability and horsepower. For a comprehensive solution, the AMSOIL Diesel Injector Clean + Cetane Boost Fuel Additive combines the benefits of both, delivering outstanding detergency and improved wear protection. Additionally, the AMSOIL Diesel Cold Flow Fuel Additive helps prevent gelling in cold weather by lowering the cold filter-plugging point.
In addition to lubrication, keeping the vehicle clean and protected is important for maintaining its value. Products like the AMSOIL Miracle Wash Waterless Wash and Wax Spray allow for easy cleaning without water, leaving a protective finish. For maintenance tasks, the AMSOIL Brake and Parts Cleaner is effective for removing oil and grease from components without leaving residue.
About the Vehicle
The 2009 Mercedes-Benz GL320 is a remarkable example of German engineering, blending the luxury of a high-end sedan with the utility of a capable off-road SUV. Introduced to the US market in 2007, the GL-Class (later renamed GLE) was positioned as a full-size luxury SUV, offering a spacious interior that could comfortably seat up to seven passengers. The GL320 specifically is powered by a 3.0-liter turbocharged V6 diesel engine, which produces a substantial amount of torque, making it ideal for towing heavy loads or navigating difficult terrain.
This model was built on a platform that shared roots with the G-Class, known for its rugged durability, but it was tuned for a more comfortable, on-road driving experience. The GL320 features a sophisticated air suspension system that automatically adjusts the vehicle’s ride height, providing a smooth ride on highways and enhanced ground clearance when off-roading. Its 4MATIC all-wheel-drive system ensures excellent traction in various weather conditions, from snow-covered roads to muddy trails.
Owners of the GL320 appreciate its versatility. It is large enough to be a family hauler, yet it retains the premium feel and high-quality materials typical of the Mercedes-Benz brand. The vehicle’s reputation for reliability, combined with its powerful and efficient diesel engine, makes it a popular choice among those who demand both performance and luxury. The GL320’s ability to handle diverse driving scenarios while maintaining a refined ride quality has solidified its place as a respected vehicle in the luxury SUV segment.
Seasonal and Storage Considerations
During periods of inactivity, such as winter storage or long-term parking, it is important to take steps to protect the engine. The AMSOIL Engine Fogging Oil is a highly effective rust preventive designed to protect internal engine components during storage. By coating the cylinder walls and valves, it prevents corrosion and ensures that the engine is ready to start when needed again. This is particularly useful for diesel engines that may be subjected to long periods of non-use.
Overall, maintaining the 2009 Mercedes-Benz GL320 with high-quality synthetic lubricants and additives is the best way to ensure its longevity and performance. By following the recommended fluid specifications and using products designed for European vehicles, owners can keep their GL320 running smoothly for years to come. The combination of superior oil, transmission fluid, coolant, and fuel additives provides comprehensive protection against the wear and tear of daily driving and extreme conditions.