I just learn a disappointing fact that passenger cars, almost most of them, are using most of the energy generated by its engine, for moving just their dead weight. Some say two third of the energy. But I prefer to believe it is most of them since the average weight of private car are around two tons while the passenger they carry is 4 time 80 kg approximately.
While the technology to make much lighter vehicle is available since long time ago. Only aircraft and sport industry seem to applicate them.
Some experts don’t believe that the weigh of the car is the only way to make car safe at higher speed.
Another major waste in world energy and major pollution source thinking that most of the passenger car are single driven ( only have one passenger) most of time.