I've run Rotella t, Delo 400, and Delvac 15/40 in my old Goldwing. Have taken it up to the redline with each oil and frankly can't tell any difference in performance. Now when it comes to shift quality, Rotella shifted notchy/ crunchy, Delo 400 was better, and Delvac 1300 shifts the best. Smoother , quiet shifts. I change the oil once a year, at between 3-4k miles. That's my story and I'm stickin to it.,,,,