Since fuel dilution is so low, the primary mechanism of viscosity loss being observed is mechanical shearing of the VII polymers.Well, what can I say. The first oil analysis is factory fill oil. The next three are from the VW dealer, which claim Castrol Edge 5W-40 on the receipt.
The next fill, I did it myself and got a jug of also Castrol Edge 5W-40 from Walmart. I did a Horizon / Oil Analyzers test on it after 5500 miles:
View attachment 96032
The viscosity, while higher than the Blackstone values, is still on the low side, while at the same time, fuel dilution is not bad. So what does this mean?
Also, this is the first time I got a significant titanium reading. Maybe I got the "fluid titanium" version from Walmart? (I threw away the jug already so can't confirm)
P.S. This test report is wrong in that I only added 0.3 qt make up oil. Though this is the first time my car burned any oil since new. Hmmm....