On Fri, 22 Dec 2006 15:06:18 GMT, "Butch Davis"
wrote:

A point of interest is that the oil on the larger diesels is usually changed
based upon the recommendation of the oil analysis lab. Most engine oil is
changed much more often than nesessary if based upon a set number of hours,
miles or days.

That makes a lot of sense for engines that are running nearly
continuously. It only takes 4 days to get to 100 hours in that kind
of service. There are times when I will do 100 hours in a week, and
others when I won't do that in 6 months.