The 2016 Subaru WRX STI is available as a 4-door, 5-seat sedan. Starting at $34,695, the 2016 Subaru WRX STI Base 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 2016SubaruWRX STISeries.HyperBlue , priced at $ 38,995 , 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.