Proper maintenance is the key to unlocking the full potential of the 2008 Infiniti FX45. This premium crossover, equipped with the robust 4.5-liter V8 engine, demands high-quality lubricants to ensure smooth operation, longevity, and safety. Using the correct fluids not only protects vital components from wear but also optimizes fuel efficiency and driving dynamics. Below is a comprehensive guide to the recommended AMSOIL products designed specifically for this vehicle.
Recommended AMSOIL Products
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Offers the highest level of protection with extended intervals of up to 25,000 miles or one year.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – Provides a balance of protection and cleaning power for intervals up to 20,000 miles.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – An economical choice that outperforms conventional oils and exceeds OEM requirements.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Formulated specifically for engines with over 75,000 miles to reduce sludge and consumption.
- AMSOIL Oil Filter – Features 99% filtration efficiency at 20 microns to keep contaminants out of the engine oil.
- WIX Oil Filter – A high-quality OEM alternative featuring premium media for improved filtration.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix formulation protecting against corrosion for up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated option for extended protection and high-temperature resistance.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Engineered for heavy towing and extreme temperatures.
- AMSOIL SEVERE GEAR 80W-90 100% Synthetic Gear Lube – Ideal for GL-5 differentials, offering superior anti-wear protection.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS responsiveness and stable viscosity across a wide temperature range.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Helps seals remain soft to prevent leaks while providing strong anti-wear protection.
Engine Oil and Filtration Recommendations
The heart of the 2008 Infiniti FX45 is the VK45DE 4.5-liter V8 engine. To keep this powerful powerplant running smoothly, AMSOIL recommends the Signature Series 5W-30 100% Synthetic Motor Oil. This oil is engineered to withstand the rigors of high-performance driving while providing up to 25,000 miles of protection between changes. For owners who prefer a slightly shorter interval but still want synthetic benefits, the Extended-Life 5W-30 100% Synthetic Motor Oil is an excellent choice, offering 37% more cleaning power to keep the engine running smoother for longer.
There is also the AMSOIL OE 5W-30 100% Synthetic Motor Oil, which fights sludge and deposits while offering a cost-effective alternative that still exceeds industry standards. If the vehicle has accumulated significant mileage, the 5W-30 100% Synthetic High-Mileage Motor Oil features a unique chemistry designed to reduce oil consumption and sludge in engines over 75,000 miles.
Filtration is equally critical. The vehicle requires a capacity of 6.1 quarts of oil, including the filter replacement. For maximum protection, the AMSOIL Oil Filter is recommended. It provides filtering efficiency of 99 percent at 20 microns, allowing for lower restriction and keeping engine parts well-lubricated. Alternatively, the WIX Oil Filter offers premium media that improves upon original equipment manufacturer standards, ensuring your engine stays clean during every change.
Transmission and Driveline Fluids
The FX45 Automatic Transmission (RE5R05A) operates under significant stress, especially during towing or spirited driving on the vehicle’s AWD system. The Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is designed to withstand heavy towing, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions. For those seeking an OE-equivalent option, the OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid protects against wear and promotes shudder-free shifts.
For the transfer case and differentials, where temperatures can run hot and pressures are high, AMSOIL SEVERE GEAR 80W-90 100% Synthetic Gear Lube is the top recommendation. It offers advanced protection against wear, controls thermal runaway, and protects against rust and corrosion. The SEVERE GEAR 75W-90 and SEVERE GEAR 75W-110 variants also provide excellent low-temperature pumpability and high-temperature stability for limited-slip applications.
Cooling and Safety Fluids
Keeping the engine at the correct operating temperature is vital for the 4.5L V8. The cooling system requires approximately 10.6 quarts. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a phosphate-, nitrate-, and silicate-free ethylene glycol pre-mix that protects all cooling system metals, gaskets, and hoses. For a longer-lasting solution, the AMSOIL Propylene Glycol Antifreeze can be used; it provides protection for up to 150,000 miles or 5 years and greatly surpasses corrosion standards.
Safety and control are paramount in an AWD vehicle. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid ensures excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range. Additionally, for the power steering system, the AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid helps seals remain soft to prevent leaks and offers strong anti-wear protection for quiet, smooth operation.
About the Vehicle
When the 2008 Infiniti FX45 rolled onto the scene, it redefined the crossover segment. Based on the Nissan F-platform, this vehicle blended the athletic handling of a sports sedan with the versatility of a sport utility. The FX45 was distinguished by its powerful 4.5-liter V8 engine, which delivered approximately 325 horsepower and 335 lb-ft of torque, offering acceleration that rivaled many performance sedans of its era.
Nissan Motor Co., Ltd., through its luxury division Infiniti, positioned the FX as a unique “Sports Coupe Crossover.” This hybrid approach gave the FX45 a lower center of gravity and more agile handling characteristics than traditional boxy SUVs of the time. The vehicle was available with either rear-wheel or all-wheel drive, with the AWD system providing confidence in various weather conditions. The interior was designed with a driver-focused cockpit, featuring supportive front seats and a layout that prioritized the driving experience.
Owners of the 2008 FX45 often cite its distinctive style, combining aggressive front-end styling with a sleek, coupe-like roofline. The 4.5-liter VK45DE engine, a DOHC unit with Variable Valve Event and Lift Control (VVEL) on the intake cam, was renowned for its smooth power delivery and linear throttle response. While it may have had a higher fuel consumption rate compared to smaller engines, the reward was a potent driving experience that felt more like a high-performance sedan than a typical utility vehicle. Regular maintenance with high-quality AMSOIL fluids ensures that this premium crossover continues to deliver its signature performance and reliability for years to come.