The Jaguar S-Type saloon was built by British car manufacturer Jaguar. It was announced in 1963, but actual deliveries didn't begin till 1964.
The S-Type came with the 3.4 or 3.8 L I6 Jaguar XK engine.
Slower and heavier than the Jaguar Mark 2, The S-Type had a better ride.
In the United States, the only engine offered was the 3.8 L engine, until the larger 4.2 L engine was introduced in the Jaguar 420.
The S-Type was replaced in August 1968 with the release of the larger Jaguar XJ6, but the name was brought back in 2000 for the retro-styled mid-range Jaguar S-Type.
Really nice page on the Jaguar 3.8 S-Type:
http://www.webfocus.co.nz/jaguar/