Originally Posted By: claluja
Anyone know how much P the Schaeffer 5w40 has to begin with? Thinking about running it in my 2014 F250 6.7.
Over the years, I've done a bunch of VOA followed by UOA of the very same oil. In each case, the readings for calcium, magnesium, phosphorus and zinc were (virtually) the same for each VOA to UOA comparison.
What you see in TiredTrucker's UOA, is most likely about what you would see in VOA of the same oil.
Boron is different, that drops from VOA to UOA. It depends on the oil, engine and length of time in use, but I've seen it over and over again. With Delo 400LE in my heavy diesels, VOA would show 500+ ppm of Boron. The UOA's would be down to 100-200 ppm. In a diesel pickup truck, the drop isn't so significant.