Created as a refined luxury engine with improved power over the EA82T, Subaru introduced the ER27 engine in November 1985 for the Subaru ACX-II concept car, shown at the Tokyo Motor Show and billed as the 'concept car of the near future.'
The concept went into production as the Subaru Alcyone VX (Subaru XT6 in North America) in August 1987, the exclusive application for the ER27.

When the ER27 was introduced, it was the only water-cooled flat-6 automobile engine on the market.
The ER27 designation was the first time Subaru incorporated the engine's displacement into the engine designation and all subsequent engine codes have retained this nomenclature.
Created as a refined luxury engine with improved power over the EA82T, Subaru introduced the ER27 engine in November 1985 for the Subaru ACX-II concept car, shown at the Tokyo Motor Show and billed as the 'concept car of the near future.' The concept went into production as the Subaru Alcyone VX (Subaru XT6 in North America) in August 1987, the exclusive application for the ER27.
When the ER27 was introduced, it was the only water-cooled flat-6 automobile engine on the market. The ER27 designation was the first time Subaru incorporated the engine's displacement into the engine designation and all subsequent engine codes have retained this nomenclature.
Subaru six-cylinder engines