I said it in one of my posts and I'll say it again. It is owner preference in the intervals to change items. By all means don't go by what I've said or do what I do.

Fseth you are correct, I do love to tinker with my rides or any ride for that matter. I change my plugs every 20-30k and oil every 5K due to the fact, my wife and I drive our vehicles hard. We live in north texas and summers are 100+. We do mix driving of highway and city with a lot of stop and go. There has been a ton of construction going on here over the past few years, which had created a lot of dirt and dust in the air. Our cars breath that shit in. This is one of the reasons why I do change things like this often. Air filters, fuel filters are the same. To me, IMO, it keeps the engine cleaner. To be quite honest, I can care less who mike miller is and what he's recommended.(not trying to start a war with you) Also, I've never stated that changing my plugs every 20-30K was preventive maint. just stated that it keeps it cleaner.

I'm in no way saying that bmw intervals are wrong. I do this for piece of mind and the fact that I enjoy toying with the rides every now and then. The methods that I've used have never failed me. I've never had any of my rides keep me stranded.