I had an early '80s Ford pickup which was converted to propane. Ford must have been still learning how to make an engine run right on unleaded or something, because this truck sucked ass stock. On propane it ran great! Propane must be kept under pressure in a purpose-built tank, which would likely occupy what is currently your back seat. In the truck it was no big deal since I had a flatbed and lots of room underneath. I have never heard of a performance car running propane, although I too have been curious as to why - perhaps propane doesn't work with high compression. Anyone care to elaborate?