The 2011 Subaru Impreza WRX STi is available as a 4-door, 5-seat sedan. Starting at $35,995, the 2011 Subaru Impreza WRX STi Hatchback is powered by a 2.5L , 4 -cylinder engine mated to a manual transmission that returns an EPA estimated 17-mpg in the city and 23-mpg on the highway. The top of the line 2011SubaruImpreza WRX STiLimited Sedan , priced at $ 37,345 , is powered by a 2.5L , 4 - cylinder engine mated to a manual transmission that returns an EPA estimated 17-mpg in the city and 23-mpg on the highway.