^^^^^^yep^^^^^^

Thats dead on the money IMO! I know for a fact that the mobil around here does something to thier petrol as quite a few people that i know including myself that went there had a loss of power and reduced Klms per tank. but another mobil a few suburbs away was fine! Bloody dodgy operators. Hence the Mobil closed down a few months ago.

I tend to go for caltex, seems to run alright on that. Have tried a few of the others, shell didnt seem as responsive, and BP didnt seem to get many klms out of tank (this was 2 years ago now) I think i may try another brand soonish, just to give tem another go, as they do change every now and again.

BP Ultimate or Vortex 98 for me.

BP Ultimate, Mobil 98 or Boost 98 for me

for those people who says their car pings on either V-power or Ultimate. You better get you car checked as it shouldn't do that on either 91, 95, or 98 octane rating.

mine's a v8 Fairlane and this is what i can say on differences:

shell V-power 98 - you can feel immediate response on WOT. It gives deep drone sound and i love it.
shell Unleaded 91 - you tend to get more mileage compared to 98 but not as good 98 in terms of extra power you get with higher octane.

BP Ultimate 98 - Preety much same performance you get from Vpower 98 BUT my car drinks it like water. I get less milelage compared to Vpower 98
BP Premium 95 - the best in terms of the amount of mileage you get out of it. I remember driving from Liverpool to Canberra then back and still have about 105km left on my tank.
BP Unleaded 91 - My car tends to rev more before it change gears. I consider this the worst fuel on my Fairlane V8.

These are just my personal opinion and it all depends how well my car is maintaned and tuned. so really, there is no such thing as a baseline for comparing petrol brands if everyone's car is maintained in different ways.

Thanks for the replies guys, I filled up with BP Premium 95 yesterday so I'll see how that one goes for me.

the only way is ks per litre on the same run,to and from work.there will be some variations,speed,traffic flow,etc but can be compared,take note of each one-----its only going to get dearer,so find the best,as stated each engine is different in many ways and so are the transmissions,wear and servicing.