Depends where you live as to which company supplies fuel BP, Shell or Caltex they all have exchange deals with each other. For instance here in Brisbane there is both a BP and a Caltex refinery. The majority of premium petrol comes from the Caltex refinery because they have a "Higher Octane Capability" whereas the BP refinery produces higher quality diesels with lower sulphur and higher Cetane number. Some fuels are imported from Singapore especially into remote cities such as Darwin which does not have its own refinery. But wherever you purchase your fuel from, ALL fuel has to meet minimum qualities prior to its leaving the distribution depot.
Yep - fuel is pretty clean, even in transportation A petrol station manager/ mate once told me The problem is that many garages have old rusted tanks or cracks in there tanks where water seeps in etc. So quality is more about what garage you get it from than brand of fuel ......and its always better to get your fuel from newer stations (newer tanks) than stations with tanks going back to 1901 and getting fuel when the tanks have just been filled, rather than from the bottom of the tank with the rest of the junk. Pays to check it every now and then by pouring some into a glass jar - if its brown with bubbles and globules - it probably isn't very good - haha Seen some pretty bad looking fuel over the time - some garages should be shut down. In small country towns there is a benefit in that often one manager of a station knows the state of the condition of everyone elses tanks - such as who has water/ cracks in there tanks, so it pays to ask around before settling down to a regular filling point
I'm not surprised -you have to consider these are not tuned for 98 unless they have an aftermarket tune. In a TT I suppose if you up the boost and want better resistance to pinging then the 98 is a good idea, but in your case you wind up with a denser (is that a real word?) fuel than what it was designed to operate with...
Denser is a word! Are you are referring to a fuels specific gravity, which will vary with atmospheric changes?
