Got 175k on ours (99 mtx). was my daughter's till 80k, mine till 160 k, my sons at present. Always used 5/30, havoline, pennzoil, motorcraft, mobil 5000, and a couple of high mileage oils. FL 400 or Supertech 8316 IIRC.
OCi every 5k, per the book (long OCI), still doesn't burn enough to add...