[HPR]

I know that my 2015 X3 N55 uses a condition based service system to schedule maintenance. The car currently has about 42,000 miles on the clock...mostly highway. My guess is that spark plug replacement notification is based on some sort of algorithm that looks at mileage, engine run time, average speed to determine highway or stop-and-go usage, etc. Should I be looking to replace plugs around the 50,000 mile mark, regardless of notification?

[Wgosma]

50K or thereabouts is about right. Your motor has direct injection so needs plugs bit shorter interval than the older port injected motors do.

I believe the coil packs are also higher voltage/capacity too....I've read they don't have as great a lifespan as those on older motors; but something you can do as needed if car hiccups or triggers fault code in future.
Good luck/Bill

[malicem3]

50k or less if you leave Auto Start/Stop on all the time.

[F30ed]

I just replaced at ~60K, you can read in below.
The reason for replace - discharge diagram was all over the place, and once I pulled plugs out it was clear why - metal build up on the tip and negative, looks as tiny metal bubbles piled up. This makes spark to jump around in unpredictable pattern between electrodes.

https://x3.xbimmers.com/forums/showt...1504218&page=6