Posted by Gilbert on February 16, 1999 at 09:50:12:
In Reply to: 99 323 Syntheic or regular oil? and Air filter Q's posted by Steve on February 16, 1999 at 09:33:52:
Your E46 already has synthetic lube in it. The BMW oil is synthetic. (That's why they claim they can change your oil at 15Kmiles.) You can't do that with a natural oil. I personally am going to stick with synthetic, but probably change oil more often than 15kmiles. In the owner's manual states that Mobil 1 is the only synthetic tested and approved by BMW as a substitute for their oil.(they are apparently in the process of testing other synthetics.) When more synthetics become approved, they list them at bmwusa.com.
As far as changing air filter--look at Alex's post a little down the page regarding switching to a K/N air filter. He has a link to Turner Motorsports as well.
I'm not sure I understand your question about the aeropackage. But the aero package is only body molding. (in theory) the molding package is supposed to aid in aerodynamics/performance. It hasn't been available for some time.