GAry,
As with most things, a lot will depend on how the equipment is used, and the time on the oil has a BIG impact as well, but you should see your oil analysis start to stabilize by the time you have 40-50 thousand miles.
I have also seen where everything looks very good, and the next analysis will show a big jump in certain elements.
Example: Had a customer whith a CTD that had 28,000 on the engine, and 9,000 on the oil. All elements were good. Next analysis engine had 37,000 and oil had 18,000 miles. All elements were fine, highest wear metal was Iron at 24 ppm, Copper was 3 ppm.
Next analysis, engine had 50,000 miles, oil had 30,000. Analysis came back with 75 ppm Iron and 169 ppm Copper, there was also 0. 21 % Volume of water. (found a bad oil cooler on engine)
Next analysis came at 53,000 on engine, and 33,000 on oil. Iron was reported at 72 ppm, Copper was down to 12 ppm and water back down to 0 %.
THis is a very good example of how well oil analysis works! Without this, and only changing oil, this would never had been detected!
Wayne
amsoilman