A gallon of gas has about 34 kWH of energy in it. Let’s say a ice passenger vehicle gets about 35mpg - so it takes about 1KWH of gas to move the car a mile. A

A gallon of gas has about 34 kWH of energy in it. Let’s say a ice passenger vehicle gets about 35mpg - so it takes about 1KWH of gas to move the car a mile. A Tesla 3 has gets takes around 25kWH to go 100mi. So about 0.25 KWh per mile. The ICE engine limitations cause it to use 400% more energy to go the same distance e. So even if gas is more dense, most of the energy is lost to engine thermodynamic limitations in using that gas - and yes mostly wasted energy in the form of heat dumping out the tailpipe.