N54 Pennzoil Ultra 5w40 v. German Castrol

I know this issue has been discussed in other forums but I couldn't find any solid info on a comparison between these two oils as they pertain to their performance and level of protection in a N54 engine. Anyone tried both of these oils and actually have lab results for them? I am trying to decide between the two and am not sure which one our high temperature, turbo charged engine will like. I live in Los Angeles so I am leaning towards the PU 5w-40 but I also realize that the GC runs thicker than usual?



Thanks in advance and I realize that the people who run GC will swear by GC and vice versa for PU but I am more interested in lab comparisons between the two rather than starting a flame war here.