there's alot to consider. I change my oil every 3-4k. that said, this last turbo at 118k or so was definitely burning oil. I still suggest pulling the dp and looking. if there is play in spool, you are going to want to swap it out. ignoring it will be the death of your engine when it goes.
258k miles - Stock engine/minor suspension upgrades/original shocks/rear struts replaced at 222k/4 passenger side wheel bearings/3 clutches/1 radiator/3 turbos