I have a 2011 BMW 550XI with just under 50000 miles and my warranty runs out real soon. After warranty I need to start doing my own oil changes and want to know the best oil for my situation. I drive mostly highway during the week around 35 miles to work and I take it to high speeds on a regular basis. I also like to occasionally track my car and do have some mods coming soon to it. I have upgraded downpipes and full exhaust and getting the ecu tuned in 2 months. I should be putting over 150 hp and around the same tq over stock when finished. I am have really liked the motul brand of oils as well as royal purple and redline. I know the BMW rating is LL-01 and they recommend 5w30 but I'm in Michigan so the weather goes from -20 F in winter to 90 F in the summer. I don't mind short intervals if it gets me more performance oriented oil that will protect my motor better. Any advice would be greatly appreciated.