Originally Posted by jeremym

One can clean the plugs. They shouldn't foul out unless there's something else wrong. Perhaps people just don't understand spark plugs...?

Why the defensive attitude? Do you know what you're talking about? That is an honest question...or are you just assuming that since they're used for X number of miles, they should be replaced? That logic is true with a lot of items on any vehicle...but not necessarily with spark plugs.

Changing out your plugs because you think they need to be replaced is like changing your lug nuts because you just think they need to be replaced.

Edit to add: changing out spark plugs used to be endorsed by BMW, and was part of their inspection II procedure. Newer engines don't foul plugs out and are much cleaner burning these days. The need for changing spark plugs isn't what it used to be.