also motor-car, "horseless carriage, wheeled vehicle which carries its own propelling mechanism," 1895 from motor (n.) + car.

"car which contains in itself a motor and a source of power," 1895, from auto- + car.

Which is it to be? We observe that the London Times has lent the weight of its authority to the word "autocar," which it now prints without the significant inverted commas but with a hyphen, "auto-car." We believe that the vocable originated with a journal called the Hardwareman, which succeeded in obtaining the powerful support of the Engineer for its offspring. As for ourselves, being linguistic purists, we do not care for hybrid constructions—"auto" is Greek, while "car" is Latin and Celtic. At the same time, such clumsy phrases as "horseless carriages," "mechanical road carriages," and "self-propelled vehicles" are not meeting with general favour. Why not therefore adopt the philogically sound "motor-car," which could be run into a single word, "motorcar"? [The Electrical Engineer, Dec. 20, 1895]

Compare automobile.

word-forming element meaning "self, one's own, by oneself, of oneself" (and especially, from 1895, "automobile"), from Greek autos, reflexive pronoun, "self, same," which is of unknown origin. It also was a common word-forming element in ancient Greek, as in modern English, but very few of the old words have survived the interval. In Greek, as a word-forming element, auto- had the sense of "self, one's own, of oneself ('independently'); of itself ('natural, native, not made'); just exactly; together with." Before a vowel, it became aut-; before an aspirate, auth-. In Greek it also was used as a prefix to proper names, as in automelinna "Melinna herself." The opposite prefix would be allo-.

late 15c. (Caxton), "capable of movement, capable of being moved, not fixed or stationary," from Old French mobile (14c.), from Latin mobilis "movable, easy to move; loose, not firm," figuratively, "pliable, flexible, susceptible, nimble, quick; changeable, inconstant, fickle," contraction of *movibilis, from movere "to move" (from PIE root *meue- "to push away"). Sociology sense of "able to move into different social levels" is by 1927. Mobile home "large trailer permanently parked and used as a residence" is recorded by 1936. Mobile phone is by 1983.

A long-distance number tapped into an Illinois Bell car telephone glowed red on a display. Satisfied that the digits were correct, I pushed the SEND button on the phone. Familiar beeps and boops emerged from the handset. Then, before a half block of this Chicago suburb had slipped by, I was in contact with my New York office. ["Take-along Telephones," Popular Science, October 1983]

1899 as shortened form of automobile (q.v.). Similar evolution yielded French, German auto.

1900, "A word used in the early days of motor vehicles for a horse-drawn vehicle" [OED], from French, from hippo- "horse" + ending from automobile.

"motor vehicle designed for travel over snow," 1931, in reference to Admiral Byrd's expedition, from snow (n.) + ending from automobile, etc.