2018 BMW M6 Convertible Complete Maintenance Schedule & Service Guide

Key Takeaways

• The 2018 BMW M6 Convertible is the final model year of the F12 generation, powered by the S63 4.4L twin-turbo V8 engine, and represents the end of an era for BMW's V8-powered grand touring convertible.
• The factory maintenance plan includes BMW Ultimate Care, which covers scheduled maintenance for 3 years or 36,000 miles from the original in-service date, with a 4-year/50,000-mile new vehicle warranty .
• BMW's Condition Based Service (CBS) system monitors actual driving conditions to determine most service intervals, though some components follow fixed mileage schedules .
• Pelican Parts recommends changing synthetic motor oil every 5,000 miles for optimal engine protection, despite CBS intervals potentially extending beyond that .
• Brake fluid requires replacement after 3 years, then every 2 years thereafter, as a time-based safety-critical service .
• Projected maintenance costs remain modest through year 4 but increase significantly in year 5, with estimates showing $3,617 for the fifth year of ownership .

Understanding the 2018 BMW M6 Convertible

The 2018 BMW M6 Convertible represents the final production year of the F12 generation 6 Series. It is powered by the S63B44T4 4.4L twin-turbo V8 engine, producing 560 horsepower in standard form and 575 horsepower in Competition Package guise. This high-performance grand tourer pairs a retractable hardtop with BMW's xDrive-like M-specific all-wheel-drive system in the Competition variant.

BMW's Maintenance Philosophy

The 2018 M6 Convertible employs BMW's Condition Based Service (CBS) system, which uses sensors and algorithms to monitor actual driving conditions—including engine temperature, driving style, trip length, and component wear—to determine when service is required. Most service intervals are determined by this system, though certain components like spark plugs and oxygen sensors follow fixed mileage schedules .

Never ignore CBS alerts. Prompt attention to service notifications prevents minor issues from developing into costly repairs.

BMW Ultimate Care & Warranty Coverage

The 2018 BMW M6 Convertible includes comprehensive factory coverage:

Projected maintenance costs for the 2018 M6 Convertible show modest expenses through the first four years, with a significant increase in year 5 as major services become due:

• Year 1: $167
• Year 2: $104
• Year 3: $104
• Year 4: $62
• Year 5: $3,617

Scheduled Maintenance Intervals

The following intervals are based on a combination of factory-specified guidance and conservative maintenance recommendations. The CBS system remains the definitive authority for your specific vehicle's needs .

Emission Control Maintenance Schedule

Based on technical documentation for the M6 Convertible, the following emission-related services follow fixed mileage intervals :

Engine Oil Service

Factory Guidance

The S63 V8 engine requires BMW Longlife-approved fully synthetic oil. The CBS system determines the exact oil change interval, and the service display indicates when an oil and filter change is due . Oil change intervals are calculated according to the service display and may extend to 10,000+ miles under normal driving conditions .

Oil Specifications: BMW recommends oils meeting BMW LL-01 approval standards. Suitable oils include those with viscosity grades appropriate for your climate, as specified in your owner's manual . Always verify the exact oil specification in your owner's manual.

Oil Filter: Always replace the oil filter simultaneously with an oil change .

Conservative Owner Guidance

Motor oil is the single most important element in keeping your engine healthy . While the CBS system may suggest intervals up to 10,000+ miles, Pelican Parts recommends changing synthetic motor oil every 5,000 miles for optimal engine protection . This is particularly important for the high-performance S63 V8, which places significant demands on oil quality.

Signs that an oil change may be needed sooner include:

• Check engine/oil change light is on
• Engine knocking sounds
• Oil smell inside the vehicle
• Excess amount of vehicle exhaust
• Frequent dusty road driving, heavy loads, or low-speed driving for long distances

Spark Plugs

Factory Guidance

The 2018 M6 Convertible's S63 V8 engine requires spark plug replacement at intervals of 60,000 miles, or at every 4th engine oil service . Some sources indicate spark plugs should be replaced with every second engine oil change .

Number of Spark Plugs: The S63 4.4L V8 uses eight spark plugs .

Recommended Spark Plugs: Bosch is a leading OEM supplier of spark plugs for BMW vehicles, including the 2018 M6 Convertible . Other OEM suppliers such as NGK also provide compatible plugs.

Conservative Owner Guidance

For vehicles driven aggressively or subjected to track use, some specialists recommend more frequent spark plug replacement than the factory interval suggests. Fresh spark plugs are a must for any good tune-up .

Symptoms of Worn Spark Plugs:

• Rough idle
• Hesitation during acceleration
• Misfires under load
• Reduced fuel economy
• Check engine lights related to cylinder misfires

Brake Fluid

Factory Guidance

Brake fluid replacement is a time-based, safety-critical service. BMW recommends replacing brake fluid after 3 years for the first time, then every 2 years thereafter .

Brake Fluid Specification: The 2018 M6 Convertible requires DOT 4 specification brake fluid . Genuine BMW Low Viscosity DOT 4 brake fluid is recommended for extreme braking conditions .

Significance: Brake fluid is hygroscopic—it absorbs moisture from the atmosphere over time. This moisture accumulation lowers the fluid's boiling point, which can lead to brake fade during spirited driving. For the M6's high-performance braking system, maintaining fresh fluid is essential for consistent stopping power.

Conservative Owner Guidance: Some specialists recommend changing brake fluid every time you service your brakes .

Engine Air Filter & Cabin Air Filter

Engine Air Filter

The engine air filter should be replaced with every second engine oil change according to the factory service schedule . A clean engine air filter ensures optimal airflow for combustion, enhancing engine efficiency and preventing contaminants from entering the engine.

Cabin Air Filter (Microfilter)

The cabin air filter (microfilter) should be replaced at every engine oil change . This filter removes pollen, dirt, and harmful airborne pollutants from the cabin air and maintains HVAC system performance. A clogged cabin filter restricts airflow through the heating and air conditioning system, reducing comfort and efficiency.

Transmission & Drivetrain Service

Automatic Transmission Fluid

The 2018 M6 Convertible is equipped with an M-specific dual-clutch transmission (DCT). For 2015-2018 models (through 12/15 production), the transmission uses Pentosin DCTF-1 equivalent fluid . Check your owner's manual for the exact transmission fluid specification for your vehicle.

Transmission Fluid Capacity: The transmission fluid capacity is approximately 8.8 liters for a new fill .

Service Consideration: While the BMW factory schedule does not specify a fixed interval for transmission fluid replacement under normal driving conditions, many independent specialists recommend transmission fluid changes at major service intervals for performance-driven vehicles.

Rear Axle Differential Oil

The rear axle differential oil should be replaced with each third engine oil change according to the factory schedule . This service is particularly important for the M6's Active M Differential, which uses electronically controlled multi-plate clutches.

Cooling System

Factory Guidance

The S63 V8 engine uses a high-performance cooling system with BMW-approved coolant. The M6 Convertible uses OEM coolant, with some 2018 models factory-filled with HT-12 Anti-Corrosion Agent . Always use the correct coolant specification for your vehicle—coolants containing HT-12 should not be mixed with other formulations .

Coolant Maintenance: Radiator coolant levels should be checked frequently and changed according to the owner's manual . Only mix concentrated coolant with distilled water .

Conservative Owner Guidance

Regular monitoring of coolant levels is recommended, and any signs of coolant leaks should be addressed promptly. The S63 V8's twin-turbo design generates significant heat, making a properly maintained cooling system essential for engine longevity.

Oxygen Sensors

Factory Guidance

The factory maintenance schedule indicates oxygen (O2) sensor replacement at 120,000 miles . A failing oxygen sensor can harm performance and fuel mileage and affect drivability.

Fuel System Maintenance

Independent Specialist Recommendation

For direct injection engines like the S63, carbon deposits can accumulate on intake valves over time. Specialists recommend periodic use of fuel system treatments containing PEA (Poly Ether Amine) technology to clean injectors, intake valves, and the combustion chamber . Regular use can help maintain optimum handling performance and fuel consumption, and can significantly reduce the risk of engine damage caused by LSPI (Low Speed Pre-Ignition) .

Long-Term Ownership Considerations

S63 V8 Engine Specifics

The 2018 M6 Convertible's S63 4.4L V8 has specific maintenance considerations:

• Valve Stem Seals: BMW has issued service bulletins regarding valve stem seal issues on the N63 and S63 engine families. Excessive oil consumption, blue smoke on startup, or blue smoke during aggressive acceleration may indicate valve seal wear.
• Turbocharger Health: The twin turbochargers are sensitive to oil quality and supply. Regular oil changes using BMW Longlife-approved oil are essential for turbocharger longevity.
• Cooling System: The S63's cooling system should be monitored regularly, as the twin-turbo design places significant demands on cooling capacity.

Frequently Asked Questions

Does the 2018 BMW M6 Convertible have a fixed maintenance schedule?

The 2018 M6 uses BMW's Condition Based Service (CBS) system, which monitors actual driving conditions and component wear to determine most service intervals. However, certain components follow fixed mileage schedules, including spark plugs at 60,000 miles and oxygen sensors at 120,000 miles .

What is the oil change interval for the 2018 BMW M6 Convertible?

The CBS system determines the oil change interval based on the service display . Pelican Parts recommends changing synthetic motor oil every 5,000 miles for optimal engine protection .

What oil does the 2018 BMW M6 Convertible use?

The S63 V8 engine requires BMW Longlife-approved fully synthetic oil meeting BMW LL-01 specifications . Always verify the exact viscosity specification in your owner's manual.

When should spark plugs be replaced on the 2018 BMW M6 Convertible?

BMW recommends spark plug replacement at 60,000 miles, or at every 4th engine oil service . Some sources indicate replacement with every second engine oil service . The S63 V8 uses eight spark plugs .

How often does brake fluid need replacing in the 2018 BMW M6 Convertible?

BMW recommends brake fluid replacement after 3 years for the first time, then every 2 years thereafter . The vehicle requires DOT 4 specification brake fluid .

When should the engine air filter be replaced?

The engine air filter should be replaced with every second engine oil change .

When should the cabin air filter be replaced?

The cabin air filter (microfilter) should be replaced at every engine oil change .

When should the rear axle differential oil be replaced?

The differential oil should be replaced with each third engine oil change .

What transmission fluid does the 2018 M6 Convertible use?

The M DCT transmission uses Pentosin DCTF-1 equivalent fluid for 2015-2018 models (through 12/15 production) . Check your owner's manual for the exact specification for your vehicle.

What warranty coverage does the 2018 BMW M6 Convertible include?

The 2018 BMW M6 Convertible includes a 4-year/50,000-mile new vehicle warranty, a 3-year/36,000-mile maintenance plan under BMW Ultimate Care, a 144-month/unlimited-mile corrosion perforation warranty, and 4 years of unlimited-mileage roadside assistance .

What are the projected maintenance costs for the 2018 BMW M6 Convertible?

Projected maintenance costs are estimated at $167 in year 1, $104 in year 2, $104 in year 3, $62 in year 4, and $3,617 in year 5 .