Maintaining the health of your 2018 Infiniti Q70 with the 3.5L VQ35HR engine requires precise fluid selection to ensure optimal performance and longevity. This luxury sedan relies on high-quality synthetic lubricants to manage the thermal stress of its powerful V6 powerplant and the intricate mechanics of its 7-speed automatic transmission. Using the wrong viscosity or fluid type can lead to premature wear, reduced fuel efficiency, and costly repairs over time.
Recommended AMSOIL Products
For the 2018 Infiniti Q70 3.5L, AMSOIL offers a complete range of synthetic lubricants designed to outperform factory specifications. Below are the recommended fluids and filters to protect your vehicle’s critical systems.
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Provides unsurpassed engine protection for up to 25,000 miles, handling extreme temperatures and minimizing horsepower loss better than conventional oils. This is the top choice for maximum performance.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Offers extended protection for up to 20,000 miles with superior cleaning power to keep the engine running smoothly and prevent sludge buildup.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – An excellent option that outperforms conventional oils and meets OEM requirements while fighting sludge and deposits effectively.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Specifically formulated for vehicles with over 75,000 miles to boost detergent power, reduce sludge, and help engines last longer.
- AMSOIL Oil Filter – Engineered for 99% efficiency at 20 microns to trap contaminants that cause wear, offering greater capacity and extended service life to match the synthetic oil.
- WIX Oil Filter – A premium aftermarket option with media that offers improvements over original equipment manufacturer (OEM)-branded filters.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Designed for the 7-speed automatic transmission, this fluid withstands heavy towing and elevated temperatures while remaining fluid in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Provides reliable protection against wear and excellent cold-weather performance for the transmission.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – A versatile option for transfer cases or other applications requiring multi-vehicle fluid compatibility.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Guards against leaks and promotes smooth, shudder-free shifts in various drivetrain components.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique OAT formulation that protects the cooling system for up to 150,000 miles, ensuring your engine stays within the optimal temperature range.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option that greatly surpasses standards for metallic corrosion and erosion.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Essential for the differential, this lube offers advanced protection against wear and controls thermal runaway.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Provides long oil, seal, and equipment life with friction modifiers for limited-slip applications.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Offers robust protection for axles and differentials under extreme loads.
- AMSOIL 75W-90 Long Life 100% Synthetic Gear Lube – Specifically engineered for extended service life, improving efficiency and seal life.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range for superior braking safety.
- AMSOIL Gasoline Stabilizer – Helps keep fuel fresh and protects against corrosion for seasonal storage.
- AMSOIL P.i.® Performance Improver Gasoline Additive – Helps restore up to 14% horsepower and cleans GDI fuel injectors to 100% flow rate, improving fuel economy and engine performance.
- AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor – Lubricates the fuel system and upper cylinders for improved performance.
Ensuring Optimal Engine Performance
The 3.5L VQ35HR engine is a robust powerplant known for its smooth power delivery and reliability. However, like any high-performance engine, it generates significant heat and stress, particularly under acceleration or during spirited driving on highways. The factory-recommended 5W-30 viscosity is designed to provide the right balance of flow at startup and protection at operating temperature. By switching to a premium synthetic alternative, you ensure that the oil maintains its viscosity more consistently across a wider range of temperatures. This is especially beneficial in regions with extreme cold winters or scorching summers. The recommended oil capacity for this engine, including the filter change, is 5.2 quarts. Selecting the right oil filter is equally critical, as a high-quality filter removes microscopic contaminants that can accelerate engine wear. The AMSOIL Oil Filter, for instance, is designed to allow lower restriction while providing high efficiency, ensuring that clean oil circulates freely to all vital engine components. For those with older vehicles, the AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil offers unique chemistry for engines over 75,000 miles, with boosted detergent packages to reduce sludge.
Protecting the Transmission and Drivetrain
Powering the rear wheels of the Infiniti Q70 is a 7-speed automatic transmission that requires fluid specifically formulated to handle its intricate gears and torque converter. The recommended fluid is a fuel-efficient synthetic type compatible with the RE7R01H specification. This transmission fluid is vital for maintaining smooth shifts and protecting internal components from wear, especially if you frequently tow heavy loads or drive in stop-and-go traffic where transmission temperatures can rise sharply. The total fill capacity for this transmission is 7.4 quarts. Using a high-quality synthetic transmission fluid like the AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid helps manage heat and ensures the fluid remains stable even under extreme abuse, preventing shudder and maintaining efficient power transfer. For the front and rear differentials, the vehicle requires GL-5 rated gear lubricants. The front differential typically holds 1.4 pints, while the rear holds 2.1 pints, with a note that synthetic oil is required for proper operation. AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube and AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube are formulated to resist rust and corrosion while controlling thermal runaway, which is crucial for the longevity of the differential gears.
Maintenance of Cooling and Safety Systems
Maintaining the proper cooling system is essential for the longevity of the engine. The 2018 Infiniti Q70 requires a specific coolant mixture to protect the aluminum engine components and various hoses from corrosion. The engine cooling system has a capacity of 9.1 quarts, while the transmission’s inverter system holds 2.7 quarts. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant provides protection for up to 150,000 miles or 5 years, making it an ideal choice for reducing the frequency of coolant flushes. This ethylene glycol-based pre-mix is compatible with all cooling system metals and is free of harsh chemicals that can damage gaskets and hoses. For those preferring a concentrated solution, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers superior protection against corrosion. Similarly, the braking system relies on high-quality fluid to function correctly. Over time, AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid absorbs moisture less than conventional fluids, maintaining stability and ensuring reliable stopping power and compatibility with modern ABS and traction control systems.
Additional Protection and Fuel Care
Beyond the standard fluid changes, the 2018 Infiniti Q70 can benefit from additives that enhance fuel combustion and protect internal components. The AMSOIL P.i.® Performance Improver Gasoline Additive is a powerful tool for maintaining fuel system cleanliness, particularly in vehicles with Gasoline Direct Injection (GDI) engines, which are prone to carbon buildup on intake valves. Adding this fuel conditioner periodically can help restore lost horsepower and improve fuel economy. The AMSOIL Upper Cylinder Lubricant Corrosion Inhibitor can further lubricate the fuel system and upper cylinders. Furthermore, for owners who store their vehicles or use them infrequently, protecting the engine during periods of inactivity is crucial. AMSOIL Engine Fogging Oil can be used to coat internal components with a protective film that prevents rust and corrosion during storage. For seasonal storage where fuel is left in the tank, AMSOIL Gasoline Stabilizer helps prevent varnish buildup. These supplemental products work in tandem with the primary lubricants to provide a comprehensive care regimen for your vehicle, ensuring that every aspect of the drivetrain and engine bay is protected against the elements and wear.
Vehicle Background
The 2018 Infiniti Q70 stands as a flagship luxury sedan in the Infiniti lineup, offering a compelling blend of Japanese engineering, powerful performance, and premium comfort. Built on the D platform, this full-size luxury sedan is designed to compete with other high-end rivals in the market, including the Mercedes-Benz E-Class and the BMW 5 Series. The Q70 is renowned for its smooth ride quality and spacious interior, making it an excellent choice for drivers who prioritize both performance and long-distance comfort.
The specific 3.5-liter V6 engine in question, the VQ35HR, is a testament to Nissan and Infiniti’s long-standing expertise in engine design. Part of the legendary VQ series, this naturally aspirated V6 delivers a robust 330 horsepower, providing ample power for confident acceleration and merging. The “HR” designation stands for High Revolution, indicating enhancements over previous iterations that allow the engine to rev more freely and deliver a more responsive throttle feel. This engine is celebrated for its smooth power delivery and reliability, making it a favorite among enthusiasts who value a naturally aspirated sound and feel. The sedan is powered through the rear wheels via a smooth-shifting 7-speed automatic transmission, which was designed to optimize fuel efficiency without sacrificing the responsive shifts expected from a luxury vehicle.
Owners of the 2018 Infiniti Q70 often appreciate its sophisticated design and the quiet, refined cabin experience. The vehicle features a suspension that effectively isolates passengers from road imperfections while maintaining sufficient body control for engaging driving dynamics. Inside, the cabin is equipped with high-quality materials, ample legroom for rear passengers, and advanced technology features that were cutting-edge for its time, including the Infiniti InTouch system.
Despite its reputation for reliability, the 2018 Infiniti Q70 can face some common issues that proper maintenance can mitigate. One prevalent concern for owners is the development of carbon buildup on the intake valves, a characteristic issue for GDI engines that can lead to rough idling and reduced performance over time. Regular use of high-quality fuel additives like AMSOIL P.i.® can help prevent this buildup. Another area of concern is the potential for oil consumption or sludge formation in the engine, particularly if the vehicle is used primarily for short trips. Using a high-performance synthetic motor oil helps mitigate these risks by providing superior cleaning agents and better resistance to thermal breakdown. Additionally, the transmission fluid can eventually degrade, leading to shuddering or delayed shifts, which can be prevented by using a durable synthetic transmission fluid that resists oxidation. Finally, the cooling system can be susceptible to corrosion or leaks if the coolant is not maintained properly, potentially leading to overheating; using a high-quality antifreeze coolant can significantly extend the life of these components and prevent costly damage.