I tend to drive hard; I live in socal, where winters are mild and summers are brutal; I do lots of stop and go driving. I came from a subaru, where 5-30 is recommended for the impreza in the US, but a 40w or higher is recommended by subaru for the same car in other locales. It has to do with subaru of american meeting cafe standards, not what's best for the car's longevity. in other words, I don't trust any manufacturer to automatically do what's best for me.
I've read lots of reports of people here using it with great effect for many years, in kmany different vehicles. Seeing as the p5 2.0l is a 30-40 engine designed for a small truck, I figured rotella might be a good fit.