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 2016 Subaru WRX STI Series.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.