[K.P.]

Well, 80% of the Australian petrol market is 91 RON. Falcons have always run at standard fuel...and I seem to remember that the Barra engine will run on down to 80 RON (meaning a non-turbo [the majority] version) can fuel up anywhere, possibly old fuel in the outback.

I don't mean to imply that 80 RON is great, just they can and will run that low.

91 RON fuel is good. A lot of people could not afford to run their cars on 95, let alone 98. Sulphation is an issue, and yes 91 contains higher sulphur levels. I still don't bother with 95.

The FG Falcon was released in February 2008. Kevin Rudd had only become Prime Minister in December 2007. How Julia Gillard could have time-travelled back to pre-release FG Falcon days, become Prime Minister instead of John Howard and/or Kevin Rudd AND "interfered" with ADR regulations (killing people and ducks...apparently) is quite a mystery! Two months would make your culprit...John Howard. I doubt the Ford Geelong plant and engineers would have had TIME to "force" 91 RON fuel onto the last Barra iteration (discounting the minor "point" upgrade to Euro V in the Mk11).

This is if we accept your hypothesis in the first place. Which ah, relies on time-travel.

I don't.