oil falling possably 60 dollars per barrel

There are manny subsitutes for oil, one main substitute being gass, bio deisel, liquified coal to deisel.
If the oil price was to remain high the country would substitute oil with gass and possably disel. Better still there is a next generation of gas deisel engines. Austraila could punnish the middle east by taking them out of the picture.

Futhermore we can not afford to have oil produced instead of crops, this would create massive inflation in food prices. The oil prices will be driven down to the extent that crops are no longer viable for fuel production.
Do not be mistaken that the powers that be will not let food supplies be threatened by oil.

For the dooms day ppl out there we have enough oil for 1000 years and petrol only attributes to 1% of enviromental polution...

Sometimes when looking for an answer its not about how or when but why. When there is a reason for a particular outcome goverments are powerful enough to force change one way or another.