It includes garbage trucks, refrigerated truck trucks, dump trucks carrying sand, concrete transporters, tankers, as well as trailers, semi-trailers, container trucks, etc. Nowadays, electric vehicles are referred to as pure electric vehicles, namely, a car that USES a single battery as the energy source for energy storage. It USES the battery as the energy source to power the motor, which drives the motor and drives the car forward. In terms of appearance, electric cars are indistinguishable from everyday cars. The difference lies mainly in the power source and the driving system. In 1934, professor rei, of the center for fluid mechanics, used model cars to measure the aerodynamic drag of various bodies in wind tunnels advertising