Main Question or Discussion Point
I know that the best engines today are only what about 20-30% efficient at converting the energy in gasoline to actual motion? Most of the energy is simply wasted as heat. So why not make an engine that is a hybrid between gas and steam? Why not use all of that thermal energy that is wasted from the combustion of gas to heat water into its vapor phase to power half of the steam engine? Could this be done practically?