Paul I always use BP Ulitmate. Why? Because it is 1.1kms from my house and I used to use Shell Opitmax but this made my old Skyline ping.

I will have no hesitation in using other brands because it's really a bee's little fella between them but no point if I have to drive out of my way.

Tim I see the biggest variable being the right foot and considering I never do more then 200kms a week I can't provide an acurate average fuel economy.