What is a muscle car

Pony cars were a "Tag" first given to the Mustang for two reasons. Both reasons interlock with each other. The little chrome horse on a small sporty car. This name stuck better than glue. When Chevy came out with the Camaro and Pontiac came out with the Firebird, the name slide over to those cars as well as there answer to the pony car.

Chrysler did not get a pony car until the Challenger and Barracuda E-body cars hit the pavement. Though considerably larger than the earlier cars, the Ford and Chevy camps cars also grew in size and the name still stuck.

Earlier (Actually all) A body cars are not pony cars. There compacts via definition at the time.