I just posted this in reference to a question on the 451 side, but wanted to be sure all you guys and gals knew it as well. Here's the posting:
One of our customers in St. Louis just reported to me that he has surpassed 100,000 miles on his 2006 450. I realize this question was probably posted for the 451 group, but thought I'd report this anyway. Good number. He's changed oil every 10,000 miles, as the manual suggests, but has made one revision to the recommendations. At his first oil change, he switched to a product called AMSOIL synthetic oil, instead of Mobil 1. The car has been operationally trouble free. He's currently at 100030 miles.
Ron Gaus, aSmartCar.com