The Mercury S-55 is an automobile that was manufactured by Mercury. Mercury added the S-55, a full-size performance / luxury vehicle to its S or "Special" line in 1962. The S-55 was first available from 1962 to 19631/2. The S-55 was not available from mid-1963 to 1965. The S-55 was re-introduced in 1966 as its own model. In 1967 while still maintaining a unique model and body code it was now available as a packaged option i.e. S-55 Performance Package. 1967 marked the end of the big "S" model.