The Holden straight-six motor is a series of straight-six engine that were produced by General Motors–Holden's in Australia between 1948 and 1986. The initial Grey motor was so dubbed because of the colour of the cylinder block, later motors came in the form of a Red, Blue, Black, and the four-cylinder Starfire engine. These engines were fitted to all Australian designed Holdens of the same years, and the four-cylinder Starfire notably also found its way into the Toyota Corona (XT130). The Grey motor is a different engine from the others, while the Red, Blue, Black, and even the Starfire are all inter-related with many common parts and castings.