The 2018 Lexus GS 300 is available as a 4-door, 5-seat sedan. Starting at $46,510, the 2018 Lexus GS 300 Base is powered by a 2.0L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 32-mpg on the highway. The top of the line 2018LexusGS 300F Sport , priced at $ 51,100 , is powered by a 2.0L , 4 - cylinder engine mated to an automatic transmission that returns an EPA estimated 21-mpg in the city and 30-mpg on the highway.