Just about 12,000 Miles now. With the Mobile One I like to change the oil every 6,000.
About 3 months ago, I called NPR's Car Talk and discussed this with the Malachi Bothers (Click and Clack). The Mobile One oil change interval, according to them, is a function of driving style. Since I run almost always on turnpike driving and do not beat up the car, they figured I would be able to go at the longer interval. However, on my other cars, I do changes every 3,000 or twice a year. The Crossfire, with the Mobile One, can go 6,000 as the Mobile One has (according to them) a great additive package and since the car has 8 quarts of oil then that even extends the change interval.