Maintaining the pristine performance of your 2018 BMW 740i requires more than just following a standard service schedule; it demands the use of lubricants specifically engineered to meet the rigorous tolerances of modern European engineering. This luxury sedan, powered by the robust B58B30M0 6-cylinder turbocharged engine, operates under significant thermal and mechanical stress. Utilizing high-quality synthetic fluids ensures that every moving component receives optimal protection, from the high-RPM demands on the crankshaft to the heat-soaked conditions of the turbocharger. Correct lubrication not only extends the lifespan of critical engine and transmission components but also maintains the vehicle’s renowned driving dynamics and fuel efficiency.
Recommended AMSOIL Products
- AMSOIL 0W-20 LS 100% Synthetic European Motor Oil – A premium oil designed specifically for the precise tolerances of European vehicles, providing superior protection against sludge and wear for this turbocharged engine.
- WIX Oil Filter – Features premium filtration media that offers improvements over original equipment manufacturer-branded filters to ensure clean oil circulation.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Engineered to withstand heavy towing, elevated temperatures, and challenging terrain while remaining fluid in sub-zero conditions.
- AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – A cost-effective option that provides excellent protection against wear for automatic transmissions like the 8HP50.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A 50/50 pre-mix formulation that protects all cooling system metals, gaskets, and hoses for up to 150,000 miles or 5 years.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated formula that requires mixing, offering extended protection up to 1,000,000 miles in heavy-duty applications or 150,000 miles in passenger cars.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides excellent ABS and traction-control responsiveness with stable viscosity over a wide temperature range.
The heart of your BMW 740i is the B58B30M0 turbocharged engine. This powerplant operates at higher temperatures and pressures than naturally aspirated engines found in previous generations. The recommended oil grade is a specific 0W-20 viscosity, with a total capacity of 6.9 quarts including the filter change. Replacing the drain plug seal is also a critical step to prevent future leaks, as the torque specification for the plug is 18 ft/lbs. The unique synthetic formulation of the AMSOIL LS European Motor Oil is crucial here, as it is designed to handle the specific additive requirements of gasoline, diesel, and hybrid European vehicles without causing harm to sensitive emission systems or sensors.
Beyond the engine, the transmission is a critical area for maintenance on this chassis. The 2018 740i utilizes an 8-speed automatic transmission (8HP50). Whether you opt for the Signature Series or the OE Fuel-Efficient fluid, ensuring the fluid level is correct is vital. The total fill for an 8-speed 8HP50 is 9.3 quarts, though service fills will vary depending on the flushing method used. These AMSOIL OE Fuel-Efficient 100% Synthetic Automatic Transmission Fluid products are formulated to handle the rigors of heavy use, providing a buffer against the high thermal loads generated during spirited driving or towing. Maintaining proper fluid integrity here prevents the clunking and hesitation that can develop as the transmission ages, preserving the smooth shift quality the vehicle is known for.
Thermal management is another pillar of longevity for this vehicle. The cooling system requires specific attention, with capacities listed as 11.9 quarts for High Thermal Capacity AMSOIL Passenger Car & Light Truck Antifreeze & Coolant (HTCC) and 4.3 quarts for Low Thermal Capacity AMSOIL Propylene Glycol Antifreeze and Engine Coolant (LTCC). Using a high-quality ethylene glycol or propylene glycol antifreeze ensures that the engine does not overheat during high-summer operations or freeze in cold climates. These formulations are phosphate-, nitrate-, nitrite-, silicate-, borate-, and amine-free, making them compatible with the diverse mix of metals and plastics found in modern cooling systems. By preventing corrosion and erosion, you protect the radiator, water pump, and heater core from premature failure.
Finally, no discussion of maintenance is complete without addressing the braking system. The 740i relies on high-performance braking dynamics, and standard brake fluids can boil under hard driving, leading to a spongy pedal and reduced stopping power. AMSOIL’s DOT 3 and DOT 4 synthetic AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid meets the BMW specific requirements for low viscosity, ensuring rapid response from the ABS and traction control systems. This fluid remains stable at extreme temperatures, offering a distinct advantage over conventional glycol-based fluids. By integrating these AMSOIL products into your maintenance routine, you are not just changing fluids; you are upgrading the vehicle’s performance envelope and ensuring it remains a reliable and safe luxury sedan for years to come.
About the Vehicle
The 2018 BMW 740i represents a significant milestone in the history of the 7 Series, marking the introduction of the new G11 generation. This model is widely regarded as one of the most advanced executive sedans ever produced, blending cutting-edge technology with traditional BMW luxury. Under the hood lies the B58 engine, a 3.0-liter twin-scroll turbocharged inline-six that has earned a reputation for being one of the finest powertrains of the modern era. Replacing the aging N55, the B58 offers a perfect balance of responsiveness, refinement, and durability, delivering roughly 335 horsepower and a robust torque curve that feels available at any RPM.
Owners of the 740i often cite the driving experience as the primary reason for choosing this vehicle. Despite its substantial size and weight, the 740i feels surprisingly nimble, largely due to its sophisticated air suspension and rear-wheel steering system. The interior is a sanctuary of craftsmanship, featuring premium leather, wood trim, and the latest iDrive infotainment system, which offers seamless connectivity and intuitive control. It is a car designed for the driver who also needs to accommodate passengers in the back, offering a level of isolation from road noise and vibration that few competitors can match.
While the vehicle is built to a high standard, owners often seek aftermarket maintenance solutions to address common issues associated with high-mileage turbocharged engines and complex electronic systems. One prevalent concern with the B58 engine, particularly in earlier production runs, involves oil consumption. The tight piston ring tolerances required for low emissions and high performance can sometimes lead to increased oil usage. Using a high-quality synthetic oil with advanced friction modifiers and high-temperature stability helps mitigate this issue by forming a more robust barrier against oil burn-off. Proper lubrication ensures that the rings remain free of carbon deposits, which is a common contributor to oil consumption problems in turbocharged direct-injection engines.
Another area where synthetic lubricants provide a tangible benefit is the cooling system. The 740i’s complex cooling architecture is designed to manage the heat of the turbo and the engine simultaneously. Over time, the plastic components in the cooling system, such as the expansion tank and thermostat housing, can become brittle. A high-quality antifreeze with superior corrosion inhibitors and pH stability helps preserve these components, preventing the slow degradation that can lead to catastrophic coolant leaks. Furthermore, the high-pressure fuel systems in these vehicles can suffer from carbon buildup on the intake valves due to direct injection. While AMSOIL P.i.® Performance Improver is the primary solution for this, starting with clean, high-quality fuel and oil reduces the rate at which carbon accumulates on other sensitive engine surfaces.
Transmission reliability is also a top priority for long-term ownership. The 8HP transmission is generally robust, but it benefits significantly from the thermal stability of AMSOIL fluids. Standard manufacturer fluids can break down under the heat of sustained highway driving or stop-and-go traffic, leading to shudder or delayed engagement. By utilizing a fluid designed for European specifications, owners can maintain the smooth, almost imperceptible shift quality that defines the 7 Series experience. This proactive approach to fluid maintenance, combining high-grade oil, filter, and transmission fluid, is the most effective strategy for preserving the value and performance of this luxury sedan.