Scott;
I use Rotella T which is a diesel grade
oil and my
oil turns black in about 200 or so miles....I asked about it and was told it had to do with the additives in the
oil itself,not that the engine is dirty.... Actually took the valve cover off my company car at 125,000 miles to replace it and the top of the head could have passed for 125 miles,it was that clean,so I know it is not the engine....I guess some oils will change colors before others, just depends on the oil,unless you have a lot of blowby,then that would affect your oil.....
Just my .02 cents......
David