Recommended fluids for 2018 Infiniti QX80 5.6L

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Maintaining the 2018 Infiniti QX80 with its 5.6-liter V8 VK56VD engine requires specific attention to fluid selection. This large, luxury SUV is designed to handle heavy loads and towing, placing significant demands on its lubrication systems. Using the correct viscosity and specifications is essential to ensure the longevity of the engine, the smooth operation of the 7-speed automatic transmission, and the reliability of the drive train under stress. AMSOIL offers a comprehensive lineup of synthetic lubricants formulated to exceed original equipment manufacturer standards, providing superior protection against wear, extreme temperatures, and the sludge formation that can plague high-mileage engines.

Recommended AMSOIL Products

Engine Oil and Filtration Requirements

The 2018 Infiniti QX80 is powered by a 5.6-liter V8 engine with the VK56VD code. This powerhouse is designed to move a substantial amount of mass, which means the engine oil must handle high operating temperatures and provide excellent shear stability. For this specific application, AMSOIL recommends a 0W-20 viscosity grade. This thinner oil is crucial for modern engines to ensure quick flow to critical components during cold starts while maintaining a protective film at operating temperatures. The oil capacity for the 2018 QX80, including the filter, is 6.9 quarts.

When selecting a motor oil, owners have several distinct options depending on their driving habits and maintenance goals. The AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil is the top-tier choice, offering the highest level of engine protection available. It is formulated to reduce horsepower loss and wear, providing up to 25,000 miles of protection or one year, whichever comes first. This level of extended drain capability is ideal for owners who push their vehicle with heavy towing or long highway commutes. It is particularly beneficial for vehicles with turbochargers, where cooling oil flow is critical.

For those seeking a slightly more economical option without sacrificing synthetic benefits, the AMSOIL Extended-Life 0W-20 100% Synthetic Motor Oil is an excellent alternative. It provides 20,000 miles of guaranteed protection and features a chemical formulation that offers 37% more cleaning power than AMSOIL OE. This helps keep internal engine parts free of deposits, ensuring the engine runs smoothly over a longer period. If you prefer a fluid that closely aligns with standard OEM maintenance intervals but still utilizes synthetic base stocks, the AMSOIL OE 0W-20 100% Synthetic Motor Oil is a reliable choice. It effectively fights sludge and deposits while outperforming conventional oils in terms of protection.

As the vehicle accumulates mileage, specifically over 75,000 miles, the engine may begin to show signs of wear or increased oil consumption. In these cases, the AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil is specifically engineered to help. It contains a boosted detergent and dispersant package to clean out old sludge and deposits, along with enhanced anti-wear additives. This unique chemistry helps reduce sludge by 67%, promoting better performance and longevity for engines that have seen significant use. It provides guaranteed protection for 12,000 miles or one year.

Choosing the correct oil filter is just as critical as selecting the right oil. A high-quality filter ensures that contaminants are trapped efficiently, preventing them from circulating back into the engine. The AMSOIL Oil Filter offers 99% efficiency at 20 microns and allows for lower restriction, which keeps engine parts lubricated and reduces the load on the oil pump. It provides greater capacity for small, wear-causing contaminants compared to competing filters. For owners who prefer a well-known aftermarket brand, the WIX Oil Filter is also compatible and offers premium media that improves over OEM-branded filters. The drain plug torque for the oil pan should be set to 25 ft/lbs, and a new washer should always be installed on the drain bolt.

Transmission and Differential Protection

The transmission in the 2018 Infiniti QX80 is a 7-speed automatic with a total fill capacity of 10.6 quarts. This transmission is designed for smooth shifting under heavy loads, and using the correct fluid is essential for maintaining shift quality and preventing internal wear. The factory recommends a specific fluid type, but AMSOIL offers synthetic alternatives that outperform conventional options in terms of temperature stability and torque converter lockup performance.

The AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is a premium choice designed to withstand the rigors of heavy towing and elevated temperatures. It remains fluid even in sub-zero temperatures, ensuring quick response times when the engine is cold. This fluid also provides reserve protection during heavy use and abuse, which is common when a large SUV is used for towing trailers or camping gear. If a more budget-friendly option is required that still meets or exceeds factory specifications, the AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid offers robust protection against wear while maintaining fuel efficiency.

For the rear differential, the vehicle requires a 75W-90 GL-5 lubricant. The capacity for the rear differential is 3.7 pints, and the use of synthetic oil is required to handle the high loads and friction within the gear set. The AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube provides advanced protection against wear and rust, helping to reduce operating temperatures and extend the life of seals and equipment. It contains friction modifiers, making it suitable for limited-slip applications. For those seeking a fluid with an extended service life, the AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube is engineered for up to 500,000 miles in over-the-road applications, offering improved seal life and better cold-weather shifting. For extreme conditions, the AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube offers an even higher viscosity for maximum protection in demanding environments.

Coolant, Brake, and Power Steering Fluids

Maintaining the cooling system is vital for the VK56VD engine, which generates significant heat. The cooling system capacity is 17.2 quarts. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a phosphate-free, silicate-free ethylene glycol 50/50 pre-mix that protects all cooling system metals, gaskets, and hoses. It offers protection for up to 150,000 miles or 5 years. For a concentrated option that requires mixing with water, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant is a non-toxic choice that provides comparable protection and can be used in both passenger cars and heavy-duty applications.

Brake fluid and power steering fluid also play crucial roles in the safety and operation of the QX80. The vehicle requires DOT 4 brake fluid. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid offers excellent responsiveness for ABS and traction control systems. It maintains a stable viscosity across a wide temperature range, ensuring consistent pedal feel in both hot and cold conditions. For the power steering system, which relies on fluid for quiet operation and leak prevention, the AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid is an ideal replacement. It helps seals remain soft to prevent leaks, resists heat for long fluid life, and provides strong anti-wear protection. It is compatible with Dexron-VI type ATF as well.

Additional Maintenance and Protection

To keep the 2018 Infiniti QX80 in peak condition, regular maintenance of the air intake and fuel system is recommended. The AMSOIL P.i.® Performance Improver Gasoline Additive is a powerful solvent that restores up to 14% horsepower and cleans GDI fuel injectors to 100% flow rate after a single tank. This helps improve fuel economy and reduces the need for higher-octane fuel. For owners who use a fuel system or upper cylinder lubricant, the AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor helps protect the fuel system and upper cylinders.

Cleanliness is also a key aspect of vehicle maintenance. The AMSOIL Engine Degreaser is a professional-strength formula that quickly removes grease, dirt, and grime from engine surfaces. For exterior care, the AMSOIL Miracle Wash Waterless Wash and Wax Spray provides a protective finish that repels dust and dirt. To protect the undercarriage from salt and corrosion, the AMSOIL Heavy-Duty Metal Protector leaves a long-lasting wax-like coating. For tire and trim care, the AMSOIL Silicone Spray protects rubber surfaces from cracking and drying without attracting dirt. The AMSOIL Power Foam® Carburetor and Induction-System Cleaner can also be used to clean deposits from the fuel system, maximizing horsepower and restoring startability.

Vehicle Background and History

The 2018 Infiniti QX80 represents the culmination of Infiniti’s luxury full-size SUV line, formerly known as the Infiniti QX56 before a name change in 2017. This vehicle is built on a truck-based platform, sharing its foundation with the Nissan Armada and Nissan Titan. This shared architecture provides the QX80 with robust towing capabilities, a standard for full-size SUVs of this era. The vehicle is powered by the reliable 5.6-liter V8 VK56VD engine, which produces a substantial amount of torque, allowing the heavy vehicle to accelerate smoothly and tow significant loads with ease.

Owners of the QX80 often appreciate the vehicle for its spacious interior, which comfortably seats up to eight passengers, and its upscale amenities that rival luxury sedans. It is a favorite among those who need a capable hauler for family vacations, towing boats or campers, or for those who require a commanding driving position. The vehicle’s reputation is built on its durability and the smoothness of its ride, despite its size. The independent front suspension contributes to a comfortable ride quality that is expected of a luxury import.

Despite its reliability, there are known issues that owners of the 2018 QX80 should be aware of, which can often be mitigated by using high-quality synthetic lubricants. One common concern is the potential for excessive oil consumption or sludge buildup in the V8 engine, particularly if the vehicle is used for short trips or severe towing without frequent fluid changes. Switching to a high-detergent synthetic oil like the Signature Series can help keep the engine cleaner for longer. Another area of focus is the front and rear differential; heavy towing can generate extreme heat, leading to premature wear on the gears and bearings. Using a premium synthetic gear lube with anti-wear additives can significantly extend the life of these components. A third common issue involves the steering system, where older fluid can lead to increased friction or seal degradation, causing whining noises or leaks; regular fluid changes with a synthetic multi-vehicle power steering fluid can resolve this. Finally, some owners report issues with the transmission shifting harshly or developing solenoid delays over time; this can often be attributed to degraded transmission fluid, which a synthetic fluid like the Signature Series Automatic Transmission Fluid can prevent by maintaining optimal viscosity and temperature resistance.

In conclusion, the 2018 Infiniti QX80 is a powerful and capable vehicle that rewards owners who prioritize proper maintenance. By selecting the correct AMSOIL synthetic fluids and filters, owners can ensure their QX80 operates at peak performance, whether it is parked in a driveway or towing a heavy trailer across the country. The comprehensive lineup of AMSOIL products covers every aspect of the vehicle’s lubrication needs, providing peace of mind and extended service intervals.

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