The Complete BMW Maintenance Schedule

Search "BMW maintenance schedule" and you'll get a dozen slightly different answers, because there isn't really one universal schedule. BMW doesn't publish a single fixed-interval list like most other manufacturers — since the early 2000s, nearly every BMW has used Condition Based Service (CBS), a system that calculates your actual service due dates from how the car is driven, not just a mileage counter.

That's genuinely a good system. It also means any generic schedule — including this one — is a starting point, not a substitute for what your specific car's computer is already calculating.

How BMW's Condition Based Service actually works

CBS isn't just tracking mileage. It factors in things like engine revs, oil temperature history, ambient temperature, and driving style to estimate real component wear — which is why two identical 3 Series cars, driven differently, can show completely different service due dates on the same day. Your iDrive service menu (or a quick OBD read) will always be more accurate for your car than any generic table, including this one.

What CBS doesn't account for is the thing most owners actually want to know before they even own the car: what should the schedule look like for this specific engine, especially on a used BMW where the service history is incomplete or unclear.

Engine oil

Use the oil-service distance and date shown by your vehicle. A fixed distance in SixLine is a preventive estimate, not a reproduction of BMW's CBS calculation. The applicable schedule depends on the model, year, market and operating conditions.

Older models need the service documentation for their own generation. A modern CBS schedule should not be applied to them automatically.

Brake fluid

Brake-fluid service is date-based. SixLine uses an adjustable 24-month preventive estimate; the initial and subsequent dates should be checked against the vehicle's service indication and model-specific documentation.

Coolant

A preventive coolant reminder is not a universal BMW replacement requirement. The BMW USA 2026 maintenance booklet treats engine coolant as a long-term fluid. Check the document applicable to your model, year and market, and use the correct coolant specification.

Spark plugs

Varies more than almost anything else on this list, because it's genuinely engine-specific. Naturally aspirated engines often go 60,000+ miles (~100,000+ km); several of BMW's turbocharged engines (the N54 in particular) have a well-documented history of wanting plugs changed closer to 30,000–45,000 miles (~50,000–70,000 km) for smooth running, well short of what the official schedule technically allows.

Transmission fluid — the "lifetime fluid" debate

BMW markets ZF automatic transmission fluid as "lifetime fill" on many models, meaning no scheduled change is built into CBS. In practice, this is one of the most argued-about points in the whole BMW ownership world — a large number of independent transmission shops and enthusiast communities recommend a change around 60,000–100,000 miles (~100,000–160,000 km) anyway, on the reasoning that "lifetime" was defined by BMW's engineers as the transmission's lifetime, not the car's. Neither position is unreasonable; it genuinely depends on how long you plan to keep the car.

Why "your BMW" and "a BMW" aren't the same schedule

A 2019 330i and a 2019 M340i share a showroom but not an engine — one runs a B46, the other a B58 — and their real-world service needs diverge more than the badge on the trunk suggests. The same is true across BMW's whole range: chassis code, engine code, and drivetrain (RWD vs xDrive) each shift specific intervals, sometimes by tens of thousands of miles.

That's the actual gap a generic schedule can't close, and it's the whole reason decoding your exact VIN matters more than most owners realize — it's the only way to know which schedule is actually yours.