Yes DD,you are correct,but my sarcasm with regards to the manufactures was that they knew they had come across a good thing with the Wankel and chose to sit on the patents/licenses to protect thier own.As for the oil crisis,lets not go there as it was and still is the biggest con in modern times controlled by the oil cartels and gleefully accepted by governments.
As a matter of interest we pay just shy of 50% of a litre to the tax collectors in OZ.How about yourselves?