Proper lubrication is the lifeblood of your 2008 Infiniti QX56. This full-size luxury SUV, powered by the robust 5.6-liter VK56DE V8 engine, is designed to handle heavy loads, long highway commutes, and off-road adventures with ease. However, like any complex machine, its longevity and performance depend heavily on the quality of fluids circulating through its systems. Using the correct oil, filters, and coolants ensures that the engine operates smoothly, transmission shifts occur without hesitation, and critical components remain protected against wear, corrosion, and extreme temperatures.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – The ultimate protection for this V8, offering up to 25,000 miles of service life and superior resistance to thermal breakdown during towing or high-load driving.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – An excellent alternative providing up to 20,000 miles of protection with enhanced cleaning power to keep the engine running smoothly for longer intervals.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – A cost-effective 100% synthetic option that outperforms conventional oils and fights sludge, ideal for maintaining OEM-level specifications.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Formulated specifically for engines with over 75,000 miles, featuring enhanced detergents and anti-wear additives to reduce oil consumption and sludge.
- AMSOIL Oil Filter – Provides 99% filtration efficiency at 20 microns and a higher contaminant capacity than competing filters to maximize engine life.
Engine Oil and Filtration
The heart of your 2008 Infiniti QX56 is the 5.6-liter V8 engine. This powerplant requires a high-quality 5W-30 viscosity oil to ensure proper flow during cold starts while maintaining a protective film at operating temperatures. The manufacturer specifies a capacity of 6.6 quarts, including the filter change. After refilling, it is crucial to check the oil level to ensure it is correct, as overfilling or underfilling can lead to performance issues.
AMSOIL offers a range of synthetic motor oils tailored to the specific needs of this vehicle. For drivers seeking maximum performance and extended drain intervals, the AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil is the top choice. It is designed to withstand the rigors of severe service, including towing, extreme heat, and cold starts, offering up to 25,000 miles of protection. This oil contains a unique additive package that provides significantly more engine protection against horsepower loss and wear compared to standard oils.
For those who prefer a balance between premium performance and value, the AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil is an outstanding option. It delivers up to 20,000 miles of protection and features enhanced cleaning agents to help keep the engine internals free of deposits. This oil is particularly effective at preventing the buildup of sludge, which can be a concern in high-mileage engines.
If your priority is to maintain strict OEM specifications while still enjoying the benefits of 100% synthetic chemistry, the AMSOIL OE 5W-30 100% Synthetic Motor Oil is designed to outperform conventional oils. It offers a robust defense against sludge and deposits, ensuring the engine stays clean and operates efficiently. Additionally, for QX56 owners whose vehicles have accumulated significant mileage, the AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil provides a specialized formulation. It includes boosted detergents and dispersants to clean out existing contaminants and anti-wear additives to protect older engine components, helping to reduce oil consumption and sludge formation.
Filtering the oil is just as important as the oil itself. The AMSOIL Oil Filter (Code: EA15K13) is engineered to capture wear-causing contaminants with a high efficiency rating. Its greater capacity allows it to hold more contaminants than many competing filters, which helps extend the life of the oil and the engine. This filter pairs perfectly with AMSOIL motor oils to provide a complete filtration solution. Alternatively, the WIX Oil Filter offers premium media that provides improvements over original equipment manufacturer-branded filters, ensuring reliable protection for your engine.
Automatic Transmission and Transfer Case
The Infiniti QX56 is equipped with a sophisticated automatic transmission (RE5R05A), a critical component for managing the power from the V8 engine. Proper fluid is essential to prevent wear, sludge accumulation, and temperature-related issues, especially when the vehicle is used for towing or off-road driving. The total fill capacity for the transmission is 11.2 quarts.
For the best protection, the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is recommended. This fluid is engineered to withstand the rigors of heavy towing, elevated temperatures, and challenging terrain. It remains fluid in sub-zero temperatures, ensuring smooth shifting in winter, and provides reserve protection during periods of heavy use. It helps to protect against wear and extends the life of the transmission components.
For a reliable option that outperforms conventional fluids, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers excellent protection against wear and helps promote smooth, shudder-free shifts. If your driving habits involve a mix of conditions, the AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid is a versatile choice that provides similar benefits with a broad compatibility range.
The transfer case is another vital component, particularly given the QX56’s four-wheel-drive capability. The fluid capacity for the transfer case is listed as 6.3 pints. While specific fluid recommendations can vary by driving condition, AMSOIL offers synthetic options that provide excellent protection. The AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid is often used in transfer cases as it resists sludge, promotes smooth operation, and guards against leaks, ensuring the transfer case operates reliably.
Differential and Gear Lubrication
The front and rear differentials require high-quality gear lube to handle the torque and stress placed on the axles. The front differential requires 3.4 pints, and the rear differential requires 3.7 pints. The QX56’s GL-5 gears demand a lubricant that can handle high loads and extreme pressure without breaking down.
For the front differential, which is rated GL-5, the AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube is a top recommendation. It provides advanced protection against wear and thermal runaway while protecting against rust and corrosion. It also contains friction modifiers for limited-slip applications, helping to reduce operating temperatures and extend the life of the seals and gears.
For the rear differential, which also requires GL-5 protection, the AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube is an excellent choice. It is specifically designed for heavy-duty applications, offering long oil, seal, and equipment life. For even more extreme protection or specific high-mileage needs, the AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube is designed for extended service intervals, providing high-load gear and bearing protection with improved seal life. If your vehicle encounters very demanding conditions, the AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube offers an even higher viscosity for maximum film strength in extreme temperatures.
Coolant and Cooling System
Maintaining the correct temperature is critical for the longevity of your 5.6L engine. The cooling system capacity for the 2008 Infiniti QX56 is 15.2 quarts. Using a high-performance coolant ensures that the engine is protected against freezing in winter and overheating in summer, while also preventing corrosion and scale buildup within the cooling passages.
The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a unique poly-organic acid (OAT) formulation designed for a wide variety of vehicles. It is a 50/50 pre-mix that protects all cooling system metals, gaskets, and hoses for up to 150,000 miles or 5 years. It is phosphate-, nitrate-, nitrite-, silicate-, borate-, and amine-free, making it compatible with all other antifreeze colors. For a more concentrated option, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers superior protection for up to 150,000 miles (or even 240,000 miles in passenger cars) and greatly surpasses standards for metallic corrosion and erosion.
Brake Fluid and Power Steering
Your braking system requires a fluid that maintains stability over a wide temperature range to ensure responsive and safe stopping power. The recommended fluid for the 2008 Infiniti QX56 is DOT 3 hydraulic brake fluid. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid provides excellent anti-lock braking system (ABS) and traction-control responsiveness. It maintains stable viscosity in extreme conditions, preventing brake fade and ensuring consistent pedal feel, which is vital for a vehicle of this size and weight.
For the power steering system, the QX56 benefits from a fluid that reduces friction and keeps seals soft to prevent leaks. The AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is formulated to reduce friction, resist heat for long fluid life, and provide strong anti-wear protection. It offers excellent high-temperature and low-temperature performance, ensuring quiet operation and preventing the common issues of hard steering or seal degradation that can occur with conventional fluids.
Additional Maintenance and Care
To keep your Infiniti QX56 in peak condition, AMSOIL offers a range of additional products. For air filtration, the WIX Air Filter offers premium media that improves upon OEM standards, ensuring clean air reaches the engine for optimal combustion. To boost fuel economy and restore lost horsepower, the AMSOIL P.i.® Performance Improver Gasoline Additive can restore fuel injectors to 100% flow rate and improve fuel economy. It is compatible with capless fuel systems and helps control pre-ignition knock.
For vehicle owners who store their QX56 seasonally, the AMSOIL Gasoline Stabilizer helps keep fuel fresh for up to 12 months, protecting against varnish and gum buildup. The AMSOIL Engine Fogging Oil provides a highly effective rust preventive for internal engine components during periods of inactivity, ensuring the engine starts smoothly when you return. For detailed care, the AMSOIL Miracle Wash Waterless Wash and Wax Spray offers a fantastic shine and tough protective finish without soap or water, while the AMSOIL Engine Degreaser allows for easy cleaning of the engine bay.
Vehicle Background
The 2008 Infiniti QX56 represents the second generation of Infiniti’s flagship full-size SUV, sharing its platform and mechanical underpinnings with the Nissan Armada. This era of the QX56 was built to compete with other large luxury SUVs by offering a blend of premium amenities, spacious interior room, and serious off-road capability. Powered by the Nissan VK56DE 5.6-liter V8 engine, it delivers substantial horsepower and torque, making it a powerful performer capable of towing significant weights and navigating rough terrain with confidence.
Owners of this vehicle often appreciate its dual nature as both a comfortable daily driver and a capable adventure machine. The interior was designed with a focus on luxury, featuring high-quality materials, advanced technology for its time, and ample cargo space for passengers or gear. The suspension system is engineered to balance ride comfort with handling stability, providing a smooth experience on paved roads while maintaining control during off-road excursions. This makes the QX56 an ideal choice for families who require a versatile vehicle that can handle everything from school runs to weekend camping trips. Its robust construction and reliable V8 engine have earned it a reputation for durability, making it a popular choice for those who prioritize performance and utility in a full-size SUV package.