its way more energy than that! car engines aren't even close to 100% efficient. all the heat that blows out your exhaust pipe is energy that the engine couldn't

its way more energy than that! car engines aren't even close to 100% efficient. all the heat that blows out your exhaust pipe is energy that the engine couldn't capture. ditto for heat of friction on the mechanical components, and heat that radiates into the air from the engine block.