Check out this column from Lubes and Greases:
http://www.amsoil.com/lit/lng_article/march_lng_new.pdf
It deals with several issues that have been discussed in "oil war" threads relating to extended oil drain intervals. The link is from the Amsoil web site, but L&G is a respected industry publication that is not connected with Amsoil. The take home message is the following: Europe has adopted extended oil change intervals using modern oil formulations. The same oils are available in the US, but marketing concerns prevent the manufacturers from recommending extended drain intervals.
http://www.amsoil.com/lit/lng_article/march_lng_new.pdf
It deals with several issues that have been discussed in "oil war" threads relating to extended oil drain intervals. The link is from the Amsoil web site, but L&G is a respected industry publication that is not connected with Amsoil. The take home message is the following: Europe has adopted extended oil change intervals using modern oil formulations. The same oils are available in the US, but marketing concerns prevent the manufacturers from recommending extended drain intervals.