I respectivly disagree. Oil tests in the majority show soot or insolubles reaching the two percent level at about 3 k miles usually. Not always mind you.
So you cannot in general have 4 percent soot a day or two after a change. I also suspect soot levels rise quicker in cold weather as the engines have some difficulty getting to their maximum burn efficency. In my opinion they would be sooting at a much higher rate in the unefficient mode. To be fair it is also mentioned that the real hazzard occurs when the soot particles clump up.
Except for the exreme cost of synthetics compared to good dino oil brought in bulk this would probably be a dead issue. I also agree with guys like Larry. Change it hot and change it often. The other component is the cost of a rebuild on these engines. They are not chev 350s. For the cost of dino oil I would do the recommended changes in the spring and summer with it. If in a cold climate I also understand a comprimise with synthetic is going to be required. That unfortunatly is a no brainer.
The bottom line is less upside to putting an expensive oil in if you let it become abrasive while in there. Or let it drop it's viscosity rating. Both will shorten an engines life to some extent. Truly false econonmy in my opinion. Also a lot of you do not remember when oil was changed every 1000 miles like I do.
Certainly oils have been improved massivly with additive packages. Contaminates still accumulate in the oils with milage and the aditive packages wear out or are consumed. The one that really concerns me is the links that control the viscosity. A diesel or at least an older one does require the viscosity far more than a gas engine. The loading of the oils is serious business in a diesel.
I wonder if anyone has done the old fashion blotter test. You simply put a drop of base oil on a blotter. Every thousand miles drop another drop on the blotter. Compare one to the other. It used to show changes. Not particularily valid for what we want to know but it also does no harm as well. You might even be suprised how the oil responds to the blotter test.

When the blotter test starts to reveal a massive change in the oil it is time for it to go. The spread rate and extent of the blotter absorption is the best indicator that the base oil has changed. Particularily in the thinning and accumulated moisture and fuel contamination areas. Also you get almost color rings as the oil spreads in the blotter material. The above are just some opinions of mine right or wrong. I certainly am not interested in fighting over them.
Also I really try to keep an open mind. Since I guess I am a dino freak it did aid my cause about wear components in the oil. It was reported that there are no wear advantages between either as the components showing up in engine anyalisis are about the same for synthetic or dino oil at the same milage. I guess it's about time to find a way to buy synthetic in bulk for the guys that want to remain there. Or at least for us canadians as it is hard to get much under 25.00 for I american gallon of synthetic and sometimes higher at present here. I can buy dino in bulk with fairly good diesel ratings and approved for most new diesel engines at 6-8 dollars per american gallon from Walmart or perhaps canadian tire in 20 litre pails. You fellows in the states can do better on that price I believe as well.
The other reason I posted this was it does seem we will always launch an oil thread from time to time. As one poster also stated on this thread he fears perhaps for his sanity as he is also starting to enjoy them. Now where is that flame suit of mine?