The 2022 BMW M340i, powered by the potent B58B30O1 2 Turbo 3.0L six-cylinder engine, is a vehicle that demands precision engineering and superior lubrication to perform as intended. To maintain the high standards of this sports sedan, it is essential to use fluids that can withstand extreme temperatures, heavy loads, and the rigorous demands of turbocharging. Using the wrong specifications can lead to premature wear, reduced performance, and costly repairs. This guide details the specific AMSOIL products designed to protect every critical component of your M340i, ensuring optimal power delivery, transmission smoothness, and long-term reliability.
Recommended AMSOIL Products
- AMSOIL 0W-20 LS 100% Synthetic European Motor Oil – A specialized formula designed for the unique demands of European vehicles, offering precise protection against the high stresses of the B58 engine.
- WIX Oil Filter – A premium filtration unit that offers improvements over original equipment manufacturer-branded filters to capture contaminants and ensure clean oil circulation.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A phosphate-, nitrate-, and silicate-free formula that protects the cooling system metals and hoses for up to 150,000 miles.
- AMSOIL Propylene Glycol Antifreeze and Engine Coolant – A concentrated antifreeze option that requires mixing with distilled water, providing extended protection up to 150,000 miles or 5 years.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Engineered to withstand the rigors of heavy towing and elevated temperatures while remaining fluid in sub-zero conditions.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Provides excellent ABS and traction-control responsiveness with a stable viscosity across a wide temperature range.
Engine Oil and Filtration for the B58 Engine
The heart of the 2022 BMW M340i is the 3.0L inline-six twin-scroll turbo engine. This powerplant is known for its high specific output and responsiveness, but it also generates significant heat. The recommended oil grade for this engine is 0W-20, which is critical for maintaining proper oil flow during cold starts and ensuring protection at high operating temperatures. The total capacity for an oil change, including the filter, is 7.6 quarts. The oil drain plug torque specification is 18 ft/lbs, and it is important to replace the drain plug seal after every service.
Using AMSOIL 0W-20 LS 100% Synthetic European Motor Oil is highly recommended for this application. This fluid features a precise blend of synthetic base oils and premium additives designed specifically for the unique demands of gasoline, diesel, and hybrid European vehicles. It offers superior protection against turbocharger bearing wear, which is a common concern in high-performance BMWs. Paired with the WIX Oil Filter (Product Code: WL10342-EA), the engine receives comprehensive filtration. The premium media in this filter offers improvements over standard OEM filters, capturing more contaminants to keep the engine internals clean. A clean engine is a long-lasting engine, and the combination of synthetic lubricant and high-efficiency filtration ensures that the B58 engine performs at its peak potential for years.
Transmission and Cooling System Protection
Powering this vehicle is an 8HP50 8-speed automatic transmission, which requires a fluid capable of handling rapid shifts and high torque loads. The total fill capacity for the transmission is 9.8 quarts. AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is the ideal choice. It remains fluid in sub-zero temperatures, ensuring smooth shifts even in winter, yet it withstands the elevated temperatures and heavy loads generated during spirited driving. This fluid provides reserve protection during heavy use, reducing the risk of sludge buildup and transmission wear.
Thermal management is equally critical. The cooling system capacity is split between two fill points: HTCC11.1 quarts and LTCC4.8 quarts. To maintain optimal operating temperatures, AMSOIL Passenger Car & Light Truck Antifreeze & Coolant (ANTPC1G) is a top recommendation. This ethylene glycol 50/50 pre-mix formulation is compatible with all other antifreeze colors and protects against corrosion for up to 150,000 miles or 5 years. For owners seeking maximum versatility, the AMSOIL Propylene Glycol Antifreeze and Engine Coolant offers a concentrated alternative that can be mixed with distilled water, providing protection up to 150,000 miles in passenger cars.
AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid and Additional Maintenance
Stopping power is just as important as acceleration. The BMW M340i utilizes a brake system that benefits from high-performance fluid. The manufacturer recommends using DOT 4 low viscosity fluid, and AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid meets and exceeds DOT 3 and DOT 4 specifications. This fluid maintains a stable viscosity over a wide temperature range, ensuring excellent ABS and traction-control responsiveness. This is crucial for a vehicle of this caliber, where brake fade can compromise safety during aggressive driving.
For those who engage in seasonal storage or want to maximize fuel economy, AMSOIL Gasoline Stabilizer and AMSOIL P.i.® Performance Improver are valuable additions. The stabilizer keeps fuel fresh for up to 12 months, while the P.i. additive helps restore up to 14% horsepower and cleans fuel injectors, which is particularly beneficial for Gasoline Direct Injection (GDI) engines. Additionally, AMSOIL Synthetic Multi-Purpose Grease and various metal protectants can be used for chassis lubrication and rust prevention, ensuring the vehicle stays in showroom condition.
Vehicle Background and History
The 2022 BMW M340i represents a significant step in the evolution of the 3 Series, bridging the gap between the standard luxury sedan and the high-performance M3 model. Built on the CLAR platform, it utilizes a rear-wheel-drive (RWD) or all-wheel-drive (xDrive) layout that provides a balanced and engaging driving character. The vehicle is powered by the legendary B58 inline-six engine, which has been a staple in BMW’s lineup since its introduction. This 3.0-liter twin-turbocharged unit produces impressive horsepower and torque figures, delivering power smoothly and linearly across the rev range.
Owners appreciate the M340i for its blend of daily usability and track-ready capability. It offers a spacious interior, high-quality materials, and advanced technology typical of the BMW brand, yet it retains the sharp handling dynamics that enthusiasts expect. The adaptive suspension and rear-wheel steering (on certain trims) contribute to a driving experience that is both refined and agile. The M340i has carved out a niche as a “driver’s sedan,” appealing to those who want performance without the daily compromises often associated with dedicated sports cars.
However, even the most robust engineering requires diligent maintenance to overcome common wear issues associated with high-performance engines. One known concern for B58 engines is carbon buildup on the intake valves, which can occur over time due to the direct injection system. Using high-quality additives and changing fluids regularly can help mitigate this issue. Another potential problem is oil consumption or leaks, particularly around the oil filter housing gasket, which is a frequent maintenance point for this engine. Using AMSOIL synthetic motor oil can help minimize leaks due to its superior lubricity and stable film strength, reducing the likelihood of oil seepage. Turbocharger health is another critical area; the B58’s turbos operate at high temperatures and speeds, making the use of a robust, high-temperature resistant synthetic oil essential to prevent oil coking and bearing failure. Finally, the cooling system, with its high heat load, requires a corrosion-resistant AMSOIL Antifreeze & Coolant to prevent galvanic corrosion and ensure efficient heat dissipation. Addressing these areas with premium lubricants can significantly extend the life and performance of this excellent German engineering marvel.