The first variant in the Chrysler 300 Letter Series family was the C-300. Introduced for the 1955 model year, the C-300 was a high performance personal luxury car. As was common at the time, Chrysler models were internally known by their "C-x" designations (Ex: C25 was the designation for the 1940 Chrysler Royal). The '300' part of the model's name is due to the 300hp produced by its 5.4L V8 (331ci) engine. The C-300, which was only available as a hardtop coupe, was now Chrysler's flagship model as the Imperial had become its own brand. Each 300 Letter Series variant was produced for one model year, and the C-300 was replaced by the Chrysler 300B.