Factory fill is not known to be Castrol, as mentioned it is speculated to be Fuchs.
QP, many current UOAs on the TDI forum show the exact same regarding Potassium in the factory fill. Those who strictly follow 10k maint. show this to normalize.
Blackstone is not know to report low fuel numbers, in fact the opposite: Blackstone rarely reports low fuel when other labs show the fuel to be flashed out.
I agree with m6pwr, the VIS and fuel are a concern as they do not match the TON of UOAs, mainly from Blackstone, that do not show the same.
Those who have a fuel dilution concern in a new CR TDI have ONE thing in common on the TDI boards, use of Bx fuel AND OR, a very cold climate.
vwthingman, have you been using a Bx fuel?