Historically, Polaris maintained a notable collaborative manufacturing partnership with Fuji Heavy Industries, the parent corporation of Subaru, which supplied high-performance four-stroke engines for several legacy Polaris ATV and snowmobile models. However, in subsequent years, Polaris transitioned heavily toward engineering and producing its own proprietary high-performance engines internally—such as the ProStar engine family—reducing its reliance on external automotive suppliers like Subaru for its primary powersports lineup.