NGK PFR6H-10.

I checked my boost using OpenSID (similar thing to reading it over OBDII though) and using a gauge to verify. That way I knew the MAP sensor on the car was reading sensible values too.

I didn't see the show myself, but i have read before that premium fuel only makes a difference on cars where it has some poke to start with.

I only use shell, as i can FEEL a huge difference with it compared to other fuel and even more so when the car needs a service.