Maintaining the peak performance of your 2008 Infiniti M45 requires more than just routine maintenance; it demands the use of premium lubricants engineered to withstand the demands of its high-revving 4.5L V8 engine. Proper fluid selection ensures optimal heat dissipation, reduces wear on critical internal components, and extends the service life of transmission and differential systems. Whether you are a performance enthusiast or a daily commuter, using the correct viscosity and specification fluids is essential for preserving the drivability and reliability of this luxury sedan.
Recommended AMSOIL Products
For the 2008 Infiniti M45 with the VK45DE engine, AMSOIL offers a comprehensive lineup of synthetic fluids designed to meet or exceed factory specifications. Below are the top recommendations for engine oil, filtration, and essential maintenance fluids.
- AMSOIL Signature Series 5W-30 100% Synthetic Motor Oil – Provides up to 25,000 miles of protection, offering superior horsepower retention and wear resistance for high-performance driving.
- AMSOIL Extended-Life 5W-30 100% Synthetic Motor Oil – A balanced option delivering 20,000 miles of protection with enhanced cleaning power to keep the engine running smoother.
- AMSOIL OE 5W-30 100% Synthetic Motor Oil – Outperforms conventional oils while fighting sludge, offering reliable protection with up to 15,000 miles between changes.
- AMSOIL 5W-30 100% Synthetic High-Mileage Motor Oil – Specifically formulated for engines over 75,000 miles to reduce leaks and sludge while restoring engine performance.
- AMSOIL Oil Filter – Delivers 99% filtration efficiency at 20 microns with a large capacity for contaminants, reducing engine wear during every oil change.
- WIX Oil Filter – A premium aftermarket alternative with high-quality media for superior protection.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mixed, ethylene glycol formulation that protects against corrosion for up to 150,000 miles or 5 years.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated, phosphate-free formula that allows for extended service intervals up to 150,000 miles in passenger cars.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands severe towing, elevated temperatures, and challenging terrain while maintaining fluidity in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Protects against wear and resists harmful sludge for reliable shift performance.
- AMSOIL Signature Series Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – Also suitable for transfer cases, withstanding thermal stress and extreme temperatures.
- AMSOIL OE Multi-Vehicle 100% Synthetic Automatic Transmission Fluid – A cost-effective option for transfer case and differential service, resisting sludge and promoting smooth shifts.
- AMSOIL SEVERE GEAR® 80W-90 100% Synthetic Gear Lube – Provides advanced protection against wear and thermal runaway, ideal for front and rear differentials.
- AMSOIL SEVERE GEAR® 75W-90 100% Synthetic Gear Lube – Offers excellent low-temperature pumpability and high-temperature stability for limited-slip applications.
- AMSOIL SEVERE GEAR® 75W-110 100% Synthetic Gear Lube – Provides ultimate protection for severe service differentials and limited-slip applications.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Ensures excellent ABS responsiveness and stable viscosity over a wide temperature range for superior braking safety.
- AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid – Formulated for quiet operation, resisting heat and keeping seals soft to prevent leaks.
Starting with the heart of the vehicle, the engine requires a fluid that can handle the thermal stresses of the VK45DE V8. The recommended AMSOIL Signature Series 5W-30 is engineered to provide up to 25,000 miles of protection, which is significantly longer than the standard intervals found in owner’s manuals. This viscosity grade is critical for maintaining proper oil pressure across all temperatures. If you prefer a slightly longer service interval or need a balance of cleaning and protection, the AMSOIL Extended-Life 5W-30 is an excellent alternative, offering 20,000 miles of guaranteed protection. For owners prioritizing OEM-like performance without the synthetic premium price, the AMSOIL OE 5W-30 offers robust sludge fighting capabilities. Finally, if your M45 has accumulated over 75,000 miles, the AMSOIL 5W-30 High-Mileage Motor Oil includes a specialized detergent package designed to clean existing deposits and condition seals.
Filtration is just as critical as the oil itself. The AMSOIL Oil Filter (EA15K13-EA) is designed to match the specific demands of this engine. Unlike standard paper filters, the AMSOIL synthetic media captures 99% of contaminants at 20 microns, allowing for lower restriction and better lubrication of engine parts throughout the extended oil change interval. For those who prefer a premium aftermarket alternative, the WIX Oil Filter (57356-EA) also offers improvements over the OEM-branded filter with high-quality media.
Moving to the cooling system, the 2008 Infiniti M45 requires a high-quality coolant to prevent corrosion in the radiator and engine block. The AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a pre-mixed 50/50 ethylene glycol solution that is compatible with all other antifreeze colors and provides protection for up to 150,000 miles. If you prefer to mix your own, the AMSOIL Propylene Glycol Antifreeze is a concentrated, non-toxic option that can last up to 150,000 miles and is free of phosphates and silicates that can damage gaskets.
The automatic transmission in the M45, specifically the RE5R05A unit, benefits greatly from synthetic fluids. The AMSOIL Signature Series Fuel-Efficient Automatic Transmission Fluid remains stable under the rigors of heavy towing and high temperatures, preventing the shudder and wear common in conventional fluids. The AMSOIL OE Fuel-Efficient Automatic Transmission Fluid offers a similar benefit at a competitive price point, resisting sludge and promoting smooth shifts. For differential service, the AMSOIL SEVERE GEAR 80W-90 and 75W-90 synthetic gear lubes are recommended for front and rear differentials. For the transfer case, the AMSOIL Signature Series Multi-Vehicle ATF or the AMSOIL OE Multi-Vehicle ATF are the correct choices. These fluids contain friction modifiers for limited-slip differentials and control thermal runaway to extend seal and equipment life.
Finally, brake and steering fluids are vital for safety and comfort. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid provides stable viscosity and excellent ABS responsiveness. For power steering, the AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid reduces friction and prevents leaks, ensuring quiet operation. Using these specific fluids ensures that every system in your Infiniti M45 operates at the highest level of efficiency and durability.
Vehicle Background
The 2008 Infiniti M45 represents a significant milestone in the luxury sedan segment, blending the sporty handling of a performance car with the refined comfort expected of the Infiniti brand. Part of the first generation of the M-series that replaced the Q45, the M45 is powered by the legendary VK45DE, a 4.5-liter naturally aspirated V8 engine. This powerplant was renowned for its smooth power delivery, high-revving nature, and robust construction, capable of generating over 300 horsepower to deliver spirited acceleration.
During the 2000s, the M45 competed directly with other premium sedans like the BMW 5-Series and Mercedes-Benz E-Class. It was built on the Nissan D platform, sharing engineering roots with the Nissan Fuga and Infiniti M35, but distinguished by its larger displacement engine and premium interior appointments. The car was celebrated for its precise steering and balanced chassis, making it a favorite among driving enthusiasts who wanted a luxury daily driver. Its 5-speed automatic transmission was designed to handle the torque of the V8 efficiently, though the fluid within requires attention to ensure long-term reliability. The M45 was also notable for its safety features and spacious rear seating, making it a practical choice for families who did not want to compromise on performance. Today, owners of the 2008 M45 continue to value this vehicle for its enduring mechanical quality, provided it receives the proper synthetic maintenance it was designed for.