I carry a wide 25 gallon plastic container with a snap on lid for oil drains. I also carry four, 2 X 12 X 15" boards. After a long drive, I drive her up on the boards. I even kick it up to high idle and let her run while I put on my coveralls, break the drain plug loose, and slide the container under the truck. Only then do I shut her down. Then I start draining the oil immediately.(let the plug drop into the oil so you don't get burned). I let her drain all night. I know, I know, IM a fanatic about all this. :-)
In the morning I reinstall the drain plug after cleaning everything. Then I remove the old filter (now cold) fill the new filter with fresh oil and install it. Then I fill her up. I take the old oil to a recycling center.
I have studied to an extent, considered and once tried syn oil in one engine. Zero difference in fuel mileage or anything I could measure.
These big diesels go eight hundred thousand to one Million miles using any good quality petroleum based oil. Hard to improve on that. I use Rotella.
Last time I checked, syn lubes are pure synthetic with no additives of any kind. I want my oil working, dispursing soot and keeping the oil from thickening. Besides, I just am not comfortable exceeding 10K miles between changes.
40 to 44 quarts of oil at Synthetic prices is not worth it, unless the engine is operated at temperature extremes.
Also IMO, an oil analysis every 3K miles is a waste of money. Oil analysis is used primarily by those who operate engines under load 6 day a week, 10 hours per day or more. Operations such as these generally do an oil analysis every, or every other, oil change. That way they can chart a history of engine wear. Internal parts that wear are made from different metals. If a certain metal increasingly shows up in the oil over time, the area of wear can be identified and corrected if necessary.
OTOH, I would never use anything but syn lube in the transmission and axles.