Steven, I have used Castrol mineral oil in my old car, had the car for 12 years and changed the oil religiously every 10,000k. Was using GTX 3 for years, which is discontinued now I believe, it was 15w40 which was fine for my last car. Traded the car recently, it had 290,000k on it and was still going strong. Speaking of service intervals, not sure about the 7,500k oil & filter changes for the Aurion, according to the book, seems excessive. Does everyone stick to this?