An automatic transmission system includes a housing containing automatic transmission fluid (ATF), a plurality of clutches configured to be engaged to generate gear ratios corresponding to forward speeds of the automatic transmission, wherein one clutch of the plurality of clutches is a friction clutch movable between a disengaged state, an engaged state utilized to create one or more gear ratios of the automatic transmission, and a slippingly engaged state between the disengaged state and the engaged state where the friction clutch is not engaged to create a gear ratio of the automatic transmission, and a controller configured to selectively move the friction clutch to the slippingly engaged state when the friction clutch is not being utilized to generate the one or more gear ratios, such that the friction clutch generates heat from friction to thereby rapidly heat the ATF in the housing and improve operating efficiency of the transmission.