Thats crap - Vortex Gold has been around for a lot longer than any of the 98 octane fuels, it was the original Premium Unleaded (if any one else remembers, Australia used to only get 95 octane till pretty recently) Vortex Gold is a pure 95 Octane fuel, and is quite good for most vehicles, not for the sportivo, but still, any normal car, it would be a waste to run it on 98, stick with the 95. Any before you ask, no im not a caltex employee im a caltex franchisee. And thanks Azza!! Finally someone with sense. everyone keeps saying that their car runs great on this and bad on that and blah blah blah. Wow. who cares. If i run my car on Caltex for 2 years and then chuck some shell in of course im gonna feel a difference. I even feel a difference with different batches of Vortex 98. How do you know your getting the same fuel? How do you know that the fuel your getting is even 98 RON? i'll also add the the whole octane RON business is pretty much a marketing gimmick as well, the real info you want is not the Research Octane Level, its the MON, or Motor Octane Level. Its all when and good to have it researched at a certian level but wouldnt you prefer to know how it is running in your engine? And also, again i'll throw this in - IF you owned a Petrol Station and you ordered your delivery load (60,000 litres) and you found you ordered too quick, and not all of it will fit, what would you do with it? You can't send it back as you have already paid for it. Where do you put it??? I can tell you where most people put it. But im not sure you want to know. Well i work with Caltex Starshop (Caltex Francise) i asked my site manager again, he said the real figures were between 95-97, really a marketing gimmick like you mentioned. I don't want to get into who knows better than who. That's just what I was told while working there for 3 years. Also nice post Azza, good to see you sat down and worked out the best for you. I had a quick question, I was told if your car isn't tuned for a certain type of petrol or octane level. There really wouldn't be any difference in the k's and performance you get from the fuel. Is this true? or a load of crap? Well your boss is exactly right.... the octane rating is never the same - hence my post about u dont know what u are getting. Both the 95 and 98 are specified as minimum octane levels. Caltex comes and tests on site every 3 months or so, and every time the figures are above what is the minimum. Best i've seen is 98.9 Octane for Vortex 98 and 96.5 for Vortex 95. the 95 is not a mixture at all, it just depends on the quality and how well they refined it, each batch will always be different.