| You can make the car engine more efficient by making it be a small generator that is working at optimal RPMs rather than the variable RPMs driving the car itself. Consider some of the various hybrid approaches. Honda has the IMA. The insight is an ICE car with an "underpowered" gas motor that has an electric motor to assist it. If it runs out of gas, it's out of gas and doesn't move. Toyota's Prius is an electric car with a gas motor that switches on when optimal. If you run out of gas in the Prius, the car will go for some further distance until the battery goes dead. The Chevy volt is an electric car with a gas generator (and a trick that can shunt some power from the gas generator to driving the car). https://www.cnet.com/roadshow/news/chevy-volts-engine-more-t... > When the battery is depleted, the range extender engine kicks in to generate electricity for the motor, as GM noted in its press materials. But when the battery is depleted and the car is running at 70 mph or above, the planetary gearset transmits additional motive force directly from the engine to the wheels. ... however, this also should take into account the efficiency of the power grid too. https://www.epa.gov/egrid/power-profiler#/ A hybrid car in part of the grid that is heavily coal can be efficient in terms of CO2 than an electric car because it is burning gas more cleanly than the grid is burning coal. |