The Packard Motor Car Company introduced their first four-cylinder engine in 1903 initially as a top level car along with the Packard Model F. It was their only automobile offered and exclusively used a four-cylinder engine from 1903 until 1912 and established Packard as a luxury car maker, and was replaced by the 1913 Packard Six.

The Packard Six was a series of luxury automobiles built over several generations by Packard from 1913 until 1947. The name was originally used to describe the car in general terms, while Series numbers were initially used and changed every year to denote wheelbases, then the number classification changed as market conditions changed so as to keep competitive with other luxury brands.