The 2007 Mercedes-Benz R320 with the 3.0L inline-six diesel turbo engine (Engine Code 642.950 H) is a sophisticated vehicle that demands precise lubrication to maintain its performance and longevity. This powertrain, part of the R-Class lineup, operates under high thermal stress and requires fluids that can withstand extreme conditions while protecting sensitive components. Using the wrong oil or fluid can lead to premature wear, reduced fuel efficiency, and costly repairs. Selecting the correct lubricants ensures that the engine, transmission, and other systems operate smoothly, whether you are driving on long highway commutes or navigating challenging terrain.
Recommended AMSOIL Products
- AMSOIL 0W-30 MS 100% Synthetic European Motor Oil – Specifically designed for the unique demands of European diesel vehicles, this oil provides superior protection against sludge and wear while extending oil change intervals.
- MANN-FILTERS Oil Filter – Features premium media that offers significant improvements over original equipment manufacturer-branded filters to ensure optimal oil flow and contaminant removal.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands the rigors of heavy towing and elevated temperatures, providing reserve protection during heavy use for the 7-speed 722.9 transmission.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – An OAT formulation that exceeds OEM requirements, protecting all cooling system metals, gaskets, and hoses for up to 150,000 miles or 5 years.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Offers excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range for safer stopping power.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Formulated to reduce friction and help seals remain soft to prevent leaks, ensuring quiet operation and long fluid life.
Essential Engine Maintenance for the 642.950 H
The heart of your R320 is the 3.0L 6-cylinder diesel engine, which benefits greatly from AMSOIL’s European formula. This specific oil is engineered to handle the precise blend of synthetic base oils and premium additives required by European manufacturers. The engine requires 9.5 quarts of oil when performing a change with a filter, and checking the level after refill is crucial for optimal operation. The drain plug torque specification is 22 ft/lbs, a detail that ensures the seal remains intact without damaging the threads.
AMSOIL 0W-30 MS provides exceptional performance across all temperature ranges. While the oil is versatile, it is particularly effective in maintaining viscosity control under the stress of a turbocharged diesel engine. The synthetic base oils resist thermal breakdown and oxidation, which are common failure points in older diesel vehicles. By choosing this oil, you are selecting a product that blows away industry standards for extreme temperature performance and severe-service protection.
Transmission and Drivetrain Protection
The R320 is equipped with a 7-speed automatic transmission (code 722.9), which requires specific fluid formulations to function correctly. There are variations based on the specific data card codes (such as A89 reduced-friction), but the capacity for a total fill is 9.5 quarts. Both the Signature Series and OE Fuel-Efficient automatic transmission fluids are recommended. These fluids are designed to withstand the rigors of heavy towing, elevated temperatures, and challenging terrain. They remain fluid even in sub-zero temperatures, ensuring that your vehicle starts and shifts smoothly regardless of the weather.
For the transfer case and differential, the R320 requires specific lubrication to handle torque distribution and wheel rotation. While capacity information for these components varies (often around 1.1 pints for the transfer case and 2.3 pints for front and rear differentials), using the correct fluid is vital. The AMSOIL transmission fluid can also be utilized for transfer case lubrication in this application, providing a unified approach to your drivetrain maintenance. The high load-carrying capability of these synthetic fluids helps prevent wear on gears and bearings, extending the life of your transfer case and differential assemblies.
Cooling System and Brake Safety
A well-maintained cooling system is critical for the longevity of your Mercedes-Benz diesel engine. The R320 requires 10 quarts of antifreeze and coolant. AMSOIL offers two excellent options: the Passenger Car & Light Truck Antifreeze & Coolant, which is a 50/50 pre-mix, or the Propylene Glycol Antifreeze and Engine Coolant, which is concentrated and requires mixing with distilled water. Both formulations protect against corrosion and erosion, safeguarding metallic components, gaskets, and hoses. They are compatible with all other antifreeze colors and do not contain phosphates, nitrates, or nitrites, which can be harmful to some cooling system components.
Braking performance is non-negotiable for a vehicle of this size and weight. The R320 requires DOT 4 plus fluid, compatible with Mercedes-Benz specifications. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is an ideal choice, offering superior high-temperature performance and low-temperature flexibility. This fluid ensures that your brake pedal feels firm and responsive, providing safety and control in emergency situations. By maintaining a high boiling point, the fluid prevents vapor lock, which can lead to brake failure.
Additional Fluids and Fuel System Care
Proper power steering fluid is essential for the R320, whether it utilizes a belt-driven pump or an electrically assisted system. AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid reduces friction and resists heat, which is vital for the longevity of the pump and seals. The fluid helps keep seals soft, preventing leaks and ensuring quiet operation. Additionally, the fuel system of a 2007 diesel vehicle benefits significantly from high-quality additives. AMSOIL offers a range of diesel fuel additives, including Diesel Injector Clean, Diesel Cetane Boost, and Diesel Cold Flow. These additives clean injectors, improve fuel economy, increase horsepower, and prevent gelling in cold weather, ensuring the engine runs efficiently and starts reliably.
About the Vehicle
The 2007 Mercedes-Benz R320 represents a unique chapter in automotive history as the brand’s first “Sport Activity Vehicle” (SAV). Positioned between a sedan and a sport utility vehicle, the R-Class offered the comfort and car-like handling of a Mercedes-Benz coupe with the versatility of a wagon. Powered by the robust 3.0L 6-cylinder diesel turbo engine, the R320 provided a blend of refined luxury and genuine utility that appealed to families and professionals alike. The vehicle’s platform was designed to offer a smooth, quiet ride, often referred to as a “floating” sensation due to its sophisticated suspension tuning.
Owners of the R320 often appreciate its spacious interior and the unique vantage point it offers compared to traditional SUVs. The diesel engine is known for its torque and fuel efficiency, making it well-suited for highway cruising and light towing. However, like any complex machine from the mid-2000s, it requires specific care to avoid common issues associated with high-mileage diesel engines. The use of high-quality synthetic lubricants can mitigate several common problems faced by owners of this model.
One prevalent issue with the 642.950 H engine is carbon buildup on the turbocharger and intake valves, a result of the diesel combustion process. AMSOIL’s premium motor oils help keep the engine internals cleaner for longer, reducing the accumulation of sludge and carbon deposits that can restrict oil flow and damage the turbo. Another common concern is the degradation of seals and gaskets in older vehicles, which can lead to oil leaks. The synthetic formulation of AMSOIL fluids is known to help maintain seal pliability, reducing the likelihood of leaks and preventing the engine from burning oil.
Furthermore, the 7-speed automatic transmission (722.9) in the R320 can sometimes exhibit shuddering or hesitation if the fluid degrades or becomes contaminated. Regular changes using AMSOIL’s high-performance transmission fluid can smooth out shifting and protect the transmission’s complex valve body from wear. Finally, the diesel fuel injectors on these vehicles are precision components that can suffer from clogging or reduced efficiency over time. The use of AMSOIL’s diesel fuel additives helps clean the injectors and maintain optimal fuel atomization, ensuring the engine retains its power and efficiency throughout its life cycle.