There's nothing too magical about the 6-cyl. bmw. I have two, well engineered, last forever, one has 185K miles, the other 130K. Neither uses oil. I have been using M1 HM 10-30, A3-B3, with excellent analysis from [censored]. No need to spend more; I change at 7500 mi. with room to spare. $22 at WM for a jug; I buy two jugs plus 1 jug of 10W-40 HM for summer blend. Try it, you'll like it.
Mike