The 2021 BMW 740i is a luxury sedan powered by a sophisticated 3.0L twin-turbocharged inline-six engine, known as the B58B30M02. This powertrain delivers impressive performance, but its complex architecture and tight tolerances demand fluids that offer superior protection. Using the correct lubricants is critical to maintaining the engine’s efficiency, ensuring the automatic transmission shifts smoothly, and preventing premature wear on high-stress components like the turbocharger and direct-injection fuel system. Proper maintenance extends the vehicle’s lifespan and preserves its driving dynamics.
Recommended AMSOIL Products
- AMSOIL 0W-20 LS 100% Synthetic European Motor Oil – A specialized formula designed specifically for the unique demands of modern European vehicles, offering precise protection for your B58 engine.
- WIX Oil Filter – Features premium filtration media that exceeds OEM standards to keep engine oil clean and protect vital components from abrasive contaminants.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – An ethylene glycol-based 50/50 pre-mix that provides extended protection up to 150,000 miles and safeguards cooling system metals.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated non-ethylene glycol option that offers superior corrosion protection and requires mixing with distilled water for ultimate safety.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Engineered to withstand the rigors of heavy towing and elevated temperatures while maintaining fluidity in extreme cold.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides stable viscosity over a wide temperature range and ensures excellent responsiveness for ABS and traction control systems.
Engine Oil and Filtration Requirements
The heart of the 2021 BMW 740i is its B58B30M02 engine, a 3.0-liter twin-turbocharged inline-six that produces significant power and torque. To keep this sophisticated engine running at its peak, AMSOIL recommends a full oil change using 0W-20 LS 100% Synthetic European Motor Oil. This specific viscosity is crucial for the B58 engine’s variable valve timing and cooling system, especially given its turbocharged nature which generates high operating temperatures. The fluid capacity for this engine, when the WIX Oil Filter is also replaced, is 6.9 quarts. It is important to ensure the drain plug is torqued to 18 ft/lbs and the seal is replaced during every service to prevent leaks. The 0W-20 LS oil features a precise blend of synthetic base oils and premium additives designed for the high-stress environments of modern European powertrains. Alongside the oil, the WIX Oil Filter (WL10342-EA) is an essential companion, offering filtration that outperforms standard OEM units to remove harmful sludge and metal particles before they can cause wear.
Cooling System Maintenance
The cooling system on the BMW 740i plays a vital role in managing the heat generated by the turbocharged engine and maintaining optimal operating temperatures. Depending on the specific build code of your vehicle, such as codes S823A8 or SA823, the AMSOIL Passenger Car & Light Truck Antifreeze & Coolant capacity can vary slightly, ranging from 8.6 quarts down to 3.2 quarts for certain configurations. It is vital to use a coolant that protects against corrosion and freeze damage while remaining compatible with the various metals and hoses in the system. AMSOIL offers two primary options for this application. The Passenger Car & Light Truck Antifreeze & Coolant is an ethylene glycol-based formula that comes as a 50/50 pre-mix, simplifying the installation process. Alternatively, the Propylene Glycol Antifreeze and Engine Coolant is a concentrated solution that requires mixing with distilled water, offering an environmentally safer alternative that provides extended protection up to 150,000 miles or five years. Both fluids are free from phosphates, nitrates, and silicates, ensuring they do not harm the engine’s components.
Transmission and Differential Lubricants
The 2021 740i relies on an 8HP50 automatic transmission, a sophisticated unit that requires precise fluid characteristics to function smoothly. For this transmission, AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is the top recommendation. A total fill for this system requires approximately 9.3 quarts, though actual replacement amounts may vary based on the specific method used. This fluid is designed to remain fluid even in sub-zero temperatures while providing a protective film that withstands the heat and stress of heavy towing or spirited driving. For the differential, the vehicle has a rear differential that holds 1.7 pints of lubricant. While specific differential fluid recommendations were not detailed in the primary fitment data, maintaining the correct lubrication in the rear differential is key to ensuring smooth power delivery and preventing gear wear over the vehicle’s long service life.
Brake Fluid and Additives
Brake safety is paramount for a vehicle of this caliber. The BMW 740i requires a DOT 4 Low Viscosity brake fluid, which is compatible with BMW Part Numbers 83 13 0 443 024 and 026. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid is an ideal choice, providing stable viscosity across a wide temperature range. This stability ensures that the brake pedal feel remains consistent and that the ABS and traction control systems respond instantly, even under extreme braking loads. Additionally, to address carbon buildup on fuel injectors, AMSOIL P.i.® Performance Improver Gasoline Additive is highly recommended. This additive restores up to 14% horsepower and cleans GDI fuel injectors to 100% flow rate after just one tank of fuel, improving fuel economy and reducing the need for higher-octane fuel.
Why Owners Choose This Vehicle and Maintenance Tips
Owners of the 2021 BMW 740i often cite the perfect balance of sportiness and comfort as the primary reason for their choice. Built on the CLAR platform, this generation of the 7 Series continues to set the standard for luxury sedans, offering a driving experience that feels agile despite its substantial size. The B58 engine is widely celebrated by enthusiasts for its reliability and responsiveness, serving as a direct replacement for the legendary N55 and predecessor to the B58 in various BMW models. The interior is renowned for its high-quality materials and advanced technology, making long commutes or cross-country trips a pleasure. However, maintaining this vehicle requires attention to detail. Common issues that can plague high-mileage turbocharged engines, such as oil consumption and carbon buildup on intake valves, are effectively mitigated by using high-quality synthetic oils and additives. Regular use of AMSOIL products helps prevent the sludge and varnish that can degrade engine performance over time. Furthermore, the vehicle’s sophisticated suspension and braking systems benefit significantly from the stability provided by AMSOIL synthetic brake fluid and grease. By adhering to a rigorous maintenance schedule with premium lubricants, owners can ensure their 740i retains its value and performance characteristics for years to come.
Vehicle Background and Performance History
The 2021 BMW 740i represents a pivotal moment in the history of the 7 Series, showcasing the refinement that has defined the flagship sedan for decades. Introduced as part of the G11/G12 generation, the 740i distinguishes itself with the 3.0L B58 turbocharged inline-six engine. This engine family has garnered a strong reputation among automotive experts and enthusiasts for its robustness and power delivery, effectively replacing the previous twin-turbo V6 in certain markets and offering a smoother, more linear power curve. The vehicle is designed with a rear-wheel-drive bias, though xDrive all-wheel-drive variants are also available, providing versatile handling capabilities in various weather conditions. The 7 Series has long been a symbol of BMW’s engineering prowess, often introducing technologies that eventually trickle down to smaller models. It competes directly with the Mercedes-Benz S-Class and the Audi A8, focusing on driver engagement without sacrificing the plush, “executive” comfort expected in this class. The 740i’s chassis is engineered to absorb road imperfections while remaining responsive during spirited driving. Inside, the cabin features advanced infotainment systems, including the latest generation of BMW iDrive, and a wide array of comfort features like executive rear seating. The vehicle is known for its smooth ride quality, thanks to its adaptive air suspension and precise steering feedback. For owners, keeping the 740i in top condition involves regular maintenance of its complex systems. The engine’s direct injection system, while efficient, can be prone to carbon buildup, making fuel additives an essential part of the maintenance regimen. The transmission, a sophisticated 8-speed automatic, requires specific fluid properties to ensure seamless shifts. Additionally, the vehicle’s reliance on synthetic fluids for its various systems is a testament to its modern engineering; using conventional fluids can lead to premature wear or performance issues. Overall, the 2021 BMW 740i is a testament to the brand’s commitment to combining luxury with high-performance engineering, rewarding owners with a driving experience that is both luxurious and exciting.