The combustion car's heat is excess heat from the engine so it is essentially free. The electric car has what amounts to a hair dryer in the dash. Yes, that is a demanding little gadget. Air conditioning is likewise run from the Volt's batteries where in a gas car it draws compressor torque from the already spinning crank. Yes, that draws gas too but you will never get more than a couple miles in a Volt or Leaf with anything like cold AC as we used to have.