I tell everyone oil is cheap ass insurance dont skimp on it and try and make it last longer. IMO mobile 1 is soso oil now days. If i used mobile 1 I would change it every 3-4k miles if driven hard.
My personal choice of oil is Rotella T6 5w40 Diesel oil. I run it in my NA slings and boosted slings as well as my 700-900HP cars. Rotella T6 works well because it is a diesel oil and had allot more lubricants and zinc. Even with this oil im changing it every couple of thousand miles.