I have always found caltex 95 works best for my bike & car.....
You Have to remember that the petrol stations themselves make nothing out of petrol....
when I use to work at 1 if we had a $20 drive off it took most of the day to make up that loss... And the higher prices get the higher the amount of drive offs. You will never successfully Boycott a NZ petrol station 2 many people have Fuel Cards.. The petrol stations make there money selling the over priced stuff in the shop.

And yes I agree remove GST of Petrol, Tax on Tax is bullshit. Also while your at it remove Tax from NZ fruit, Veg, Meat and Dairy