2018 BMW M240i xDrive Convertible Service Requirements & Maintenance Schedule

Key Takeaways

• The 2018 BMW M240i xDrive Convertible is powered by the B58 3.0L turbocharged inline-six engine and uses BMW's Condition Based Service (CBS) system, which calculates maintenance needs based on actual driving conditions rather than fixed mileage alone .
• The original factory warranty included 4 years/50,000 miles of basic and powertrain coverage, along with 3 years/36,000 miles of complimentary scheduled maintenance.
• A mandatory 1,200-mile running-in service is required for the M240i, including engine oil and filter replacement, rear axle fluid change, and intercooler inspection.
• Pelican Parts recommends changing synthetic motor oil every 5,000 miles for the B58 engine, which is more conservative than the CBS system's typical 10,000-mile interval .
• Brake fluid replacement is a critical time-based service recommended every 2 years, using DOT 4 Low Viscosity fluid that meets BMW specifications.

Understanding the BMW Condition Based Service System

The 2018 BMW M240i xDrive Convertible is equipped with the Condition Based Service (CBS) system, which represents a modern evolution from traditional fixed-interval maintenance. Sensors and special algorithms take into account the driving conditions of the vehicle, and CBS uses these to calculate the need for maintenance. The system makes it possible to adapt the amount of maintenance corresponding to your user profile .

The system monitors factors such as driving style, fuel consumption, and trip length to determine when maintenance is actually needed. This results in variations from the base 10,000-mile interval, meaning two identical vehicles may require service at different odometer readings depending on how they have been driven. Information on required maintenance is continuously stored in the remote control, and a service center can read this data to suggest the appropriate maintenance scope for the vehicle .

The vehicle is equipped with a service interval warning system as standard equipment . Because the CBS system is the primary guide for your specific vehicle, the reference intervals provided below should be used for planning purposes, but the CBS system remains the primary indicator for when service is required.

Factory Maintenance Coverage

The 2018 BMW M240i xDrive Convertible originally came with comprehensive factory coverage:

The scheduled maintenance program covered factory-recommended services including oil changes, filter replacements, brake fluid, and spark plugs as indicated by the CBS system.

Engine and Drivetrain Specifications

B58 Engine Overview

The 2018 M240i xDrive Convertible is powered by the B58 3.0L turbocharged inline-six engine, producing 335 horsepower at 5,500 rpm and 369 lb-ft of torque . This engine features M Performance TwinPower Turbo technology with a twin-scroll turbocharger, direct injection, VALVETRONIC fully variable valve control, and Double-VANOS variable camshaft timing .

The vehicle is equipped with the xDrive all-wheel-drive system as standard, paired with an 8-speed Steptronic Sport automatic transmission . The xDrive system adds a transfer case and front differential, which require additional fluid service consideration.

Engine Oil Specifications

The B58 engine requires BMW-approved synthetic oil. Key specifications include:

Approved oil specifications for the B58 engine include BMW LL-01, LL-01 FE, LL-17FE+, and LL-22 FE++. BMW 0W-20 LL-17FE+ is the factory-recommended oil for many B58 applications, with 0W-30 also being a commonly approved viscosity.

Brake Fluid

The 2018 M240i xDrive Convertible requires DOT 4 Low Viscosity brake fluid that meets BMW specifications. Genuine BMW brake fluid exceeds DOT 4 specifications and is designed for the vehicle's braking system.

Service Interval Summary

1,200-Mile Running-In Service (Mandatory)

The 2018 BMW M240i xDrive Convertible requires a running-in service at approximately 1,200 miles. This service is critical for the long-term health of the vehicle and includes:

• Engine oil and filter replacement
• Rear axle fluid (differential) replacement
• Intercooler inspection

During the break-in period, it is recommended to vary engine speeds and avoid full throttle or kickdown. This service is mandatory and must be documented to maintain warranty coverage.

Engine Oil and Filter Service

Factory Schedule: The CBS system is the primary indicator for oil change intervals, with service typically indicated around 10,000 miles or 12 months depending on driving conditions.

Owner Guidance: Pelican Parts recommends changing synthetic motor oil every 5,000 miles for the B58 engine . This is a conservative approach particularly beneficial for the turbocharged engine. Always replace the oil filter when changing the oil.

You may need an oil change sooner than recommended if you notice the check engine or oil change light is illuminated, hear knocking sounds from the engine, smell oil inside the vehicle, or observe excess vehicle exhaust. Frequent heavy hauling, dusty road driving, or extended low-speed trips can also shorten oil life.

Brake Fluid Service

Brake fluid replacement is a critical time-based service for the 2018 M240i xDrive Convertible.

Factory Schedule: BMW recommends brake fluid replacement at intervals indicated by the CBS system, typically every 2 years. The vehicle requires DOT 4 Low Viscosity brake fluid that meets BMW specifications. Brake fluid is hygroscopic, meaning it absorbs moisture from the air over time, which can lower its boiling point and lead to brake fade under hard use.

Owner Guidance: For owners who participate in spirited driving or track events, consider replacing brake fluid annually, particularly if using high-performance fluids with a higher boiling point. If brake fluid appears black or brown, it indicates significant contamination and the need for immediate service.

Spark Plug Service

Spark plugs are crucial for engine ignition. The B58 engine's turbocharged nature means spark plugs endure more heat and pressure compared to naturally aspirated engines.

Factory Schedule: BMW recommends spark plug replacement at intervals indicated by the CBS system. General guidance suggests replacing spark plugs about every 30,000 miles for performance-oriented BMW engines.

Owner Guidance: For the M240i, replacing spark plugs on time is critical for maintaining performance. If your BMW has been tuned for increased performance, replacing the spark plugs ahead of the factory interval is recommended. A consistent, strong spark is essential for the B58 engine as it relies on good ignition timing to make power.

Engine Air Filter and Cabin Air Filter

Engine Air Filter: The engine air filter should be inspected and replaced as indicated by the CBS system. In dusty operating conditions or for vehicles with an aftermarket induction kit, more frequent inspection and replacement may be warranted.

Cabin Air Filter: The cabin air filter should be replaced at regular intervals, typically as indicated by the CBS system. If you notice a musty smell when running the air conditioning, it is likely time to replace the cabin filter.

ZF 8-Speed Transmission Fluid Service

The ZF 8-speed automatic transmission in the M240i is a sophisticated gearbox offering smooth shifts and rapid response.

Factory Schedule: BMW does not specify a fixed replacement interval for automatic transmission fluid under normal operating conditions; the fluid is often designated as a "lifetime" fill.

Owner Guidance: Many independent specialists recommend a fluid and filter service at approximately 60,000 miles as a preventive measure. For vehicles that see track use, more frequent intervals are recommended.

xDrive System Fluid Service

The 2018 M240i xDrive Convertible's all-wheel-drive system includes a transfer case and front differential, which require additional fluid service consideration.

Factory Schedule: BMW may indicate transfer case and front differential fluid replacement as part of the CBS system recommendations.

Owner Guidance: For long-term reliability, independent specialists recommend replacing the transfer case and front differential fluids approximately every 60,000 miles as part of preventive maintenance planning.

Cooling System Service

The B58 engine requires proper cooling system maintenance. BMW recommends coolant replacement at intervals indicated by the CBS system, typically every 4 years or 60,000 miles. Using Genuine BMW coolant/antifreeze is recommended to maintain cooling system performance. The coolant should be flushed and replaced according to the CBS system or at preventive intervals.

Storage Period Considerations

If the vehicle battery has been disconnected, storage periods are not taken into account by the CBS system. In this case, a BMW service center should update the time-dependent maintenance procedures, such as checking brake fluid and, if necessary, changing the engine oil and the microfilter/activated-charcoal filter .

Maintenance Schedule Summary Table

Long-Term Ownership Considerations

Service Documentation

Maintaining complete service records is essential for warranty compliance and resale value. BMW service centers can read CBS system data stored in the vehicle's remote control to verify maintenance history . A full service history supports the vehicle's mechanical condition and reliability.

Track Use Considerations

For owners who regularly track their M240i, additional maintenance considerations apply:

• Oil changes should be performed before and after track events
• Brake fluid should be replaced annually with high-temperature fluid
• Brake pads should be inspected before each track event
• Transmission and differential fluid changes should be performed more frequently

B58 Engine Common Issues

While the B58 engine is generally reliable, several components require attention as the vehicle ages. The B58 engine is sensitive to oil quality, and using non-approved oil can compromise engine protection. Regular maintenance with quality oil and proper coolant helps mitigate risks.

xDrive System Maintenance

The xDrive system adds complexity and requires attention to additional components not present on rear-wheel-drive models. The transfer case and front differential require periodic fluid service. Transfer case fluid should be replaced at appropriate intervals to help prevent premature wear and damage caused by contaminated or broken-down lubricant.

Cooling System Maintenance

The B58 engine's cooling system is critical for performance and reliability. Coolant levels should be monitored regularly, and small leaks should not be ignored. The cooling system should be flushed and the coolant replaced according to the CBS system or every 4 years as a preventive measure. Use BMW-approved phosphate-free coolant to prevent corrosion in aluminum engine components.

Frequently Asked Questions

What engine is in the 2018 BMW M240i xDrive Convertible?

The 2018 BMW M240i xDrive Convertible is powered by the B58 3.0L turbocharged inline-six engine producing 335 horsepower and 369 lb-ft of torque .

How does the Condition Based Service system work?

The CBS system uses sensors and algorithms to monitor driving conditions, driving style, and fuel consumption to calculate service needs dynamically. It stores service data in the remote control and displays requirements on the Control Display, adapting maintenance to your specific driving profile .

What is the 1,200-mile running-in service for the M240i?

The 1,200-mile running-in service is a mandatory service that includes engine oil and filter replacement, rear axle fluid replacement, and intercooler inspection. This service is critical for the long-term health of the vehicle and must be documented to maintain warranty coverage.

What type of oil does the 2018 BMW M240i xDrive Convertible require?

The B58 engine requires BMW-approved synthetic oil meeting LL-01, LL-01 FE, LL-17FE+, or LL-22 FE++ specifications. Approved viscosities include 0W-20 and 0W-30. Always refer to your owner's manual for the exact specification.

How often does the 2018 BMW M240i xDrive Convertible need an oil change?

The CBS system typically indicates oil changes around 10,000 miles or 12 months depending on driving conditions. For maximum engine protection, Pelican Parts recommends changing synthetic oil every 5,000 miles .

How often should brake fluid be changed?

BMW recommends brake fluid replacement at intervals indicated by the CBS system, typically every 2 years. The vehicle requires DOT 4 Low Viscosity brake fluid that meets BMW specifications.

When should spark plugs be replaced?

Spark plugs should be replaced as indicated by the CBS system. For the turbocharged B58 engine, a more aggressive replacement schedule of approximately 30,000 miles is recommended, particularly for tuned vehicles.

When should the transmission fluid be changed on the M240i xDrive?

BMW does not require automatic transmission fluid changes under normal conditions. For long-term reliability, many specialists recommend a fluid and filter service at approximately 60,000 miles as a preventive measure.

What happens if the vehicle battery is disconnected?

Storage periods during which the battery was disconnected are not taken into account by the CBS system. A BMW service center should update the time-dependent maintenance procedures, such as checking brake fluid and, if necessary, changing the engine oil and microfilter .

What was the original warranty coverage for the 2018 M240i xDrive Convertible?

The 2018 BMW M240i xDrive Convertible came with a 4-year/50,000-mile basic and powertrain warranty, 12-year/unlimited-mile corrosion perforation warranty, 4-year/unlimited-mile roadside assistance, and 3-year/36,000-mile complimentary scheduled maintenance.