The Amsoil 3000 Series HDD 5W-30 is an excellent oil (expensive though).
I would not worry about the 5W-30 for two reasons (many VW TDIers do use this oil) but that is just my view.
1. Amsoil's 5W-30 is actually thicker than many other synthetic 5W-30 at 100 deg C. Its kinematic viscosity at 100 deg C is 11.4 cSt compared to the 9.7 cSt of Mobil 1 5W-30, for example.
2. Your climate, like mine, is cool (or cold) enough to use this 5W-30.
The API guide for minimum viscosity is 9.3 cSt for a 30 weight and 12.5 cSt for a 40 weight, at 100 deg C. Amsoil's number is right between these two.