Their overall design has a lot to do with why hybrid cars are so popular as well. Specifically, they tend to be quite aerodynamic — which, yes, can benefit cars and other vehicles just as much as airplanes and things like that. In this case, the design makes for far less drag, plus typically, the tires are comprised of a very special type of rubber, which allows for less friction — in other words, you can save on tires as well!