2013 BMW 335i Convertible Service Requirements & Maintenance Schedule

Key Takeaways

• Condition Based Service (CBS): Your 2013 335i Convertible uses BMW's CBS system, which uses sensors and algorithms to determine service intervals based on your individual driving conditions. The system tracks engine oil, front/rear brake pads, brake fluid, and vehicle checks .
• Engine: The 2013 335i Convertible (E93) is powered by the N55 3.0-liter twin-scroll turbocharged inline-six engine, producing 300 horsepower and 300 lb-ft of torque. Power is sent to the rear wheels through a six-speed Steptronic automatic transmission .
• Oil Change: BMW's CBS system determines the interval. A forum member reported their CBS indicated an oil change at approximately 17,000 miles, but many specialists recommend a more conservative 10,000-mile interval or annual change .
• Brake Fluid: Brake fluid should be replaced when indicated by the CBS system, with a general recommendation of every 2 years as brake fluid absorbs moisture from the air .
• Transmission Fluid: Some resources recommend automatic transmission fluid and filter service every 30,000–50,000 miles to prevent slipping and component wear .

Understanding BMW's Condition Based Service (CBS) System

The 2013 BMW 335i Convertible does not follow a traditional fixed-mileage maintenance schedule. Instead, it uses the Condition Based Service (CBS) system. Sensors and special algorithms take the different driving conditions of your BMW into account. Condition Based Service uses this to determine the current and future service requirements, creating a service regimen that reflects your own individual driving profile .

CBS Tracked Service Items:

• Engine oil
• Brake pads: separately for front and rear
• Brake fluid
• Vehicle check
• Legally mandated inspections depending on local regulations

Important Service Notes:

• Storage periods during which the vehicle battery was disconnected are not taken into account by the CBS system. If this occurs, have a service center update time-dependent maintenance procedures such as brake fluid checks and, if necessary, changing the engine oil and microfilter .
• BMW recommends that service work be performed only by your BMW center or at a workshop that works according to BMW repair procedures with correspondingly trained personnel .

Engine Oil Service

BMW Factory Schedule

The CBS system will determine the precise oil change interval based on your driving conditions. Some owners have reported intervals as long as approximately 17,000 miles between changes, although CBS calculations vary based on driving style and conditions .

Oil Specifications

The N55 engine requires synthetic oil meeting BMW Longlife-01 (LL-01) approval. In the UK market, common viscosities approved under LL-01 include 0W-30, 5W-30, 0W-40, and 5W-40. A widely accepted choice is 5W-30 or 5W-40 synthetic oil meeting the LL-01 standard .

Oil Capacity: Approximately 6.5 liters with filter.

Owner Guidance

Although the CBS system may allow for extended intervals, many independent specialists and experienced owners recommend a more conservative approach. BMW reduced its recommended interval to 10,000 miles for 2014 model year vehicles produced July 2013 and later. Since your 2013 model may have been built just before this change, a 10,000-mile or annual oil change is a prudent recommendation .

If the vehicle is driven mostly on short trips or in city traffic, more frequent oil changes are recommended to protect the N55 engine.

Brake Fluid Service

BMW Factory Schedule

Brake fluid replacement is a time-based service tracked by the CBS system. BMW recommends replacement at the intervals indicated by the system.

Owner Guidance

Brake fluid should be checked regularly and replaced when indicated by the CBS system or if it has been more than 2 years since the last change. Brake fluid is hygroscopic, meaning it absorbs moisture from the air, which can cause corrosion and reduced braking performance . If the fluid appears dark in color, a change is recommended.

Spark Plug & Ignition System Service

Owner Guidance

Spark plugs and ignition coils are critical for engine performance. Weak coils or worn plugs can cause misfires, rough idle, hard starts, and poor fuel economy. New coils and plugs restore crisp throttle response and cleaner emissions . Replacing spark plugs and ignition coils together is recommended for maintaining peak performance.

The estimated cost for a spark plug replacement on a 2013 BMW 335i xDrive (similar engine) ranges from approximately $356 to $516 at a shop or dealer .

Transmission Service

BMW Factory Schedule

BMW designates the automatic transmission fluid as "lifetime fill" for normal operation, with no specified replacement interval in the standard maintenance schedule.

Owner Guidance

Your 2013 335i Convertible is equipped with a six-speed Steptronic automatic transmission . For long-term reliability, regular transmission fluid and filter changes are recommended by many independent specialists. Recommended intervals include :

• Transmission Fluid Change: Every 30,000 miles to prevent transmission slipping
• Transmission Filter Replacement: Every 30,000 or 50,000 miles

Signs Transmission Service Is Needed:

• Transmission fluid leaks (fluid under the vehicle)
• Delayed gear shifts
• Odd noises or grinding sounds when shifting
• Burning smell from transmission fluid
• Transmission warning light

General Service Recommendations Summary

The CBS system is the ultimate authority for your specific vehicle. The following table provides context for common service intervals based on specialist guidance :

Frequently Asked Questions

1. How often should I change the oil in my 2013 BMW 335i Convertible?

The CBS system determines the interval based on driving conditions, potentially up to approximately 17,000 miles. However, many independent specialists recommend a 10,000-mile or annual oil change for the N55 engine .

2. What oil does the 2013 BMW 335i Convertible require?

The N55 engine requires synthetic oil meeting BMW Longlife-01 (LL-01) approval. Common viscosities include 5W-30, 5W-40, 0W-30, and 0W-40 .

3. When should the brake fluid be replaced?

Brake fluid replacement is tracked by the CBS system. If it has been more than 2 years since the last change, or if the fluid appears dark, a change is recommended .

4. How does the CBS system work?

The CBS system uses sensors and algorithms to monitor driving conditions and determine service needs. It tracks engine oil, brake pads, brake fluid, and vehicle checks separately .

5. When should the transmission fluid be changed?

BMW designates it as "lifetime fill," but many specialists recommend transmission fluid and filter service every 30,000–50,000 miles to prevent slipping and component wear .

6. Should I replace spark plugs and ignition coils at the same time?

Replacing ignition coils simultaneously with spark plugs is recommended as preventative maintenance. Weak coils or worn plugs can cause misfires, rough idle, and poor fuel economy .

7. What is the estimated cost of spark plug replacement for my 2013 335i?

The estimated cost for spark plug replacement on a 2013 BMW 335i xDrive ranges from approximately $356 to $516 depending on service provider .

8. Is the 2013 BMW 335i Convertible expensive to maintain?

Maintenance costs are above average for non-luxury vehicles but typical for premium German sports cars. Regular preventative maintenance is the key to extending vehicle life and avoiding costly repairs.

9. What transmission is in the 2013 BMW 335i Convertible?

The 2013 335i Convertible is equipped with a six-speed Steptronic automatic transmission .

10. What are signs my transmission needs service?

Common signs include fluid leaks under the vehicle, delayed gear shifts, grinding noises when shifting, a burning smell, or the transmission warning light .

*Always consult your vehicle's owner's manual and CBS system for the most accurate maintenance requirements for your specific 2013 BMW 335i Convertible. Maintenance needs may vary by production date and driving conditions.*