In message , Dave Plowman
writes

Showing just how inefficient a petrol engine is.

Perhaps you'd better set about a more efficient way of converting a
high density fuel like petrol to mechanical energy, then. Electric
vehicles driven off storage batteries have been around for nearly as
long. If they were capable of being developed into a viable competitor,
it would have been done years ago.
Try diesel. Or indeed any compression ignition engine.
--
Clive