I have had the SDL for about four months and am still learning all kinds of things about it. I recently changed its oil for the first time and put in Rotella synthetic, right up to the "do not exceed" line. I was quite careful in this process because I wanted to determine the oil consumption the next day when I took it on a 400 mile trip.

So, I finish the trip and check the level after letting it sit for 12 hours and find, to my chagrin, that the level is about 24 oz. less than when I started. Not a good sign.

I add no oil, hoping that it will burn less oil on the return 400 mile trip with the level closer to the "do not go below" line.

I check it after returning home and letting it sit for 12 hours. The level has now increased so that it is now down only about 6 oz. from the oil change.

Very interesting phenomenon. I have figured it out. Anybody want to hazard a guess? I will tell you in advance that it is not water or any other contaminant in the oil (to the best of my knowledge and belief).