Maintaining the high-performance 2018 BMW 750xi requires more than just standard maintenance intervals; it demands fluids specifically engineered to handle the extreme thermal and mechanical stresses of a twin-turbo V8 engine and sophisticated xDrive all-wheel-drive system. This luxury sedan is a powerhouse, but its longevity depends heavily on the quality of lubricants used during service. Utilizing premium synthetic lubricants ensures that critical components like the N63B44B engine, the 8-speed automatic transmission, and the differential systems operate with reduced friction, optimal cooling, and maximum protection against wear. For owners of this vehicle, selecting the right products is the most effective way to preserve the car’s dynamic driving character and reliability over the long term.
Recommended AMSOIL Products
- AMSOIL 0W-30 MS 100% Synthetic European Motor Oil – The primary engine oil recommended for this vehicle, specifically formulated for the tight tolerances and high heat of European turbocharged engines. It provides exceptional protection against sludge and deposits while maintaining optimal viscosity in all temperatures.
- WIX Oil Filter – An essential companion to the AMSOIL motor oil, this filter offers superior media and construction to trap contaminants effectively, ensuring the engine receives clean oil flow for extended service intervals.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mixed glycol solution that provides corrosion protection for the aluminum-intensive cooling system of the 7 Series, safeguarding against rust, scale, and freeze damage up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – An excellent concentrated alternative for those who prefer mixing their own coolant, offering superior heat transfer properties and protection against erosion for up to 1,000,000 miles in heavy-duty applications.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Designed to withstand the rigors of the 8-speed GA8HP75Z transmission found in this model, this fluid reduces friction and heat buildup while ensuring smooth shifting and reserve protection during heavy use.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A cost-effective yet high-performance alternative that provides the same level of wear protection and thermal stability as the Signature Series for this specific transmission application.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Meets and exceeds BMW’s requirements for low viscosity DOT 4 fluid, offering a high boil point to prevent brake fade under the heavy braking loads encountered by a vehicle of this mass and power.
The 2018 BMW 750xi is equipped with a 4.4-liter N63B44B biturbo V8 engine that generates substantial power. To keep this engine running at its peak, the oil capacity with a filter change is 11.1 quarts. It is crucial to adhere to these specific fluid volumes to ensure proper lubrication and heat dissipation. The engine oil should be an AMSOIL 0W-30 MS, chosen for its ability to protect European vehicles against the unique demands of modern, high-output engines. The drain plug torque should be 15 ft/lbs, and the seal must be replaced every time to prevent leaks. Using a high-quality filter like the WIX 57189 ensures that the oil remains clean, protecting the turbochargers and the V8’s variable valve timing systems from abrasive wear.
Beyond the engine, the cooling system of the 750xi holds approximately 9.7 quarts of fluid. Maintaining this system is vital because the N63 engine runs hot, and efficient heat exchange is critical for performance and reliability. The recommended coolant options include both the pre-mixed AMSOIL Passenger Car & Light Truck Antifreeze & Coolant and the concentrated AMSOIL Propylene Glycol Antifreeze and Engine Coolant. Both formulations are phosphate, nitrate, and silicate-free, making them safe for all the metals, gaskets, and hoses found in the BMW cooling system. These fluids offer protection for up to 150,000 miles or 5 years, which aligns well with the vehicle’s durability expectations.
For the transmission, the 8-speed automatic gearbox (GA8HP75Z) is a complex mechanical system that benefits significantly from synthetic lubrication. A total fill for this transmission requires 9.2 quarts of fluid. AMSOIL offers two excellent choices: the Signature Series Fuel-Efficient fluid and the OE Fuel-Efficient fluid. Both are designed to withstand the high temperatures and heavy loads generated by the 750xi, ensuring that the transmission shifts smoothly and remains protected even during spirited driving or towing scenarios. Proper transmission fluid extends the life of the gearbox and maintains the vehicle’s renowned handling characteristics.
AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is another critical component often overlooked. The 2018 750xi requires a low-viscosity DOT 4 fluid that meets BMW specifications (83 13 0 443 024 or 026). This fluid provides excellent responsiveness and a high boiling point, which is essential for a heavy luxury sedan that may be driven aggressively. This fluid maintains stable viscosity over a wide temperature range, preventing the brake fade that can occur during repeated hard stops.
About the Vehicle: 2018 BMW 750xi
The 2018 BMW 750xi represents the pinnacle of the F01/F02 generation of the 7 Series, a vehicle that has long defined the luxury sedan segment. Produced by BMW AG, a renowned German automobile manufacturer based in Munich, the 7 Series is BMW’s flagship full-size luxury car. The “xi” designation signifies that this model is equipped with BMW’s xDrive all-wheel-drive system, which intelligently distributes power between the front and rear axles to provide exceptional traction and stability in various weather conditions. The 2018 model year falls within the later years of the F01 chassis lifecycle, just before the introduction of the next-generation G11 model, making it a highly desirable vehicle for enthusiasts who appreciate the refined engineering of this era.
Under the hood of the 750xi lies the potent N63 4.4-liter twin-turbocharged V8 engine. This powerplant is celebrated for its smooth power delivery, rapid acceleration, and high top-end output. The engine produces a significant amount of horsepower and torque, making the 750xi one of the fastest sedans in its class. Despite its immense power, the 7 Series is engineered to offer a comfortable, isolated ride, utilizing advanced suspension systems and sound insulation to dampen road imperfections. The interior is crafted with high-quality materials, including premium leather, wood trim, and advanced technology features that enhance driver and passenger convenience. This blend of luxury and performance has made the 750xi a favorite among business executives and driving enthusiasts alike.
However, the complexity of the N63 engine and the sophistication of the 7 Series chassis come with specific maintenance requirements that owners must adhere to. One of the most common issues reported with the N63 engine is carbon buildup on the intake valves and fuel injectors, which can lead to rough idling, reduced fuel economy, and a loss of power over time. Using AMSOIL P.i. Performance Improver fuel additive regularly can help mitigate this issue by cleaning the injectors and preventing carbon deposits from forming, helping to maintain the engine’s efficiency and responsiveness.
Another area of concern for this model is oil consumption. The N63 engine has been known to consume oil at a higher rate than some other engines, particularly as the vehicle accumulates mileage. This is often due to the high operating temperatures and the design of the piston rings. AMSOIL 0W-30 MS synthetic oil is designed to resist thinning and evaporation better than conventional oils, which can help minimize oil consumption and extend the time between necessary top-offs. Additionally, the synthetic oil’s superior film strength provides better protection for the engine’s moving parts, reducing wear on critical components like the turbochargers and variable valve timing actuators.
Owners of the 2018 750xi may also experience issues with the cooling system. The high thermal loads generated by the twin-turbos place significant stress on the cooling system, and leaks or corrosion can develop over time. Using a high-quality antifreeze like AMSOIL’s Propylene Glycol formulation helps protect the aluminum engine components from corrosion and ensures that the system maintains its boiling and freezing points, even under extreme conditions. This proactive approach to cooling system maintenance can prevent costly repairs associated with overheating, which is a known risk for this engine if not properly managed.
Furthermore, the xDrive all-wheel-drive system in the 750xi includes transfer case components that require proper lubrication. While the specific fluid recommendations for the transfer case are critical, ensuring that the differential fluids are topped up with the correct lubricants helps maintain the smooth operation of the powertrain. The rear differential holds approximately 1.9 pints, and the front differential holds about 1.3 pints, though specific fluid types should be verified based on the vehicle’s exact configuration. By addressing these potential problem areas with high-performance synthetic fluids, owners can enjoy the full potential of their 750xi for years to come, avoiding the common pitfalls associated with high-performance luxury vehicles.
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