Lubrication for the 2018 BMW M3 extends far beyond just the engine crankcase. The S55B30 engine, while robust, requires strict maintenance protocols to handle the immense torque generated by its twin-scroll turbochargers. The oil capacity for this engine is 6.9 quarts when changing the filter, a specific volume that ensures proper lubrication levels once the system is refilled. It is important to note that torque specifications for the drain plug vary depending on the sump pan material; magnesium pans require 15 ft-lbs, while aluminum pans require 18 ft-lbs. After refilling the system, checking the oil level is a mandatory step to ensure the sensor reads accurately and the engine is protected.
Essential Fluids for Performance and Durability
Beyond the engine, the cooling system of the M3 plays a vital role in managing the thermal load of the twin turbos. The system requires approximately 14.7 quarts of AMSOIL Passenger Car & Light Truck Antifreeze & Coolant. For optimal protection, owners should choose between a pre-mixed ethylene glycol formulation or the AMSOIL Propylene Glycol Antifreeze. Both options provide extended service intervals, protecting against corrosion, rust, and scale buildup that can lead to costly overheating issues. Using the correct antifreeze ensures that the delicate aluminum components of the cooling system and engine block remain free from galvanic corrosion, which is common in European vehicles.
Transmission and differential maintenance are equally critical for the driving experience of the M3. While specific transmission fluid recommendations are not detailed for all configurations, the differential requires specific attention. The rear limited-slip differential, often designated as the 215M, requires a specific synthetic AMSOIL SEVERE GEAR 75W-140. The capacity is approximately 2.1 pints for the 215M rear differential. AMSOIL SEVERE GEAR is engineered to handle the extreme pressure in limited-slip applications, providing a stable film that reduces operating temperatures and prevents the “whining” or chatter often associated with worn or improperly lubricated differentials. This gear lube contains friction modifiers that ensure smooth engagement, enhancing the car’s launch characteristics and cornering stability.
AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid degradation is a common issue in high-performance vehicles, as the heat generated during spirited driving can boil the fluid, leading to a spongy pedal or complete brake fade. The M3 benefits significantly from this product. This fluid maintains a stable viscosity across a wide temperature range, ensuring consistent pedal feel and ABS responsiveness even under the most severe track conditions. By preventing fluid boiling and maintaining hydraulic integrity, this synthetic brake fluid helps eliminate the risk of brake failure, providing peace of mind during high-speed maneuvers.
About the Vehicle
The 2018 BMW M3 represents the pinnacle of BMW’s M Division engineering during this era. Based on the F80 platform, this generation of the M3 was powered by the S55B30, a 3.0-liter twin-turbocharged inline-six engine. This engine was a significant departure from the naturally aspirated V8s of the previous generation, offering a power band that is both wide and punchy. The S55 engine produces substantial horsepower and torque, delivering acceleration figures that rival many sports cars, all while retaining the everyday drivability expected from a luxury sedan. The M3 is known for its sharp handling, rear-wheel-drive bias (with optional xDrive all-wheel drive), and a chassis that is tuned to balance comfort with aggressive performance.
Owners of the 2018 M3 often appreciate the car’s dual nature as a daily driver that can transform into a track weapon. The sedan body style offers practicality, with four doors and a trunk, making it versatile for various driving scenarios. The interior is driver-focused, featuring supportive bucket seats and high-quality materials that age gracefully. The car’s reputation is built on its reliability relative to its performance level and its ability to provide instant throttle response from the turbocharged setup.
However, the unique design of the S55 engine and the high-performance nature of the vehicle introduce specific maintenance challenges. One common issue with the S55 engine is the oil pan. Some models feature a magnesium oil sump pan, which is lighter but requires specific torque specifications and sealing ring replacements to prevent leaks. The aluminum sump pans are also common but have their own torque requirements. Failure to respect these torque values during an oil change can lead to gasket failures and significant oil loss.
Another area where premium lubricants make a difference is in the valve cover gaskets. High heat can degrade rubber seals over time, leading to oil leaks that stain the engine bay. Using a high-quality AMSOIL 0W-30 MS that resists oxidation and thermal breakdown can help maintain the flexibility of these gaskets for longer periods. Additionally, the high-output turbochargers place immense stress on the oil supply. Proper AMSOIL Oil Filter usage ensures that the turbo bearings remain well-lubricated even during hard acceleration, preventing premature turbo failure, which is a concern for any high-mileage M3.
Furthermore, the M3’s limited-slip differential can be prone to shudder or chatter if the gear oil degrades or lacks the proper friction modifiers. This issue is particularly noticeable during low-speed turns. Using a dedicated limited-slip gear lube like AMSOIL SEVERE GEAR helps eliminate these noises and extends the life of the clutch packs within the differential. Finally, brake fluid absorption of moisture is a known issue in many vehicles, but it is critical in a car that sees heavy braking. A synthetic brake fluid with a high boiling point ensures that the braking system remains responsive, preventing the loss of pedal travel that can occur with standard DOT 3 or DOT 4 fluids under repeated hard stops.