The 2017 Lexus GS 450h is available as a 4-door, 5-seat sedan. Starting at $63,635, the 2017 Lexus GS 450h Base is powered by a 3.5L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 29-mpg in the city and 34-mpg on the highway. The top of the line 2017 Lexus GS 450h F Sport, priced at $68,680, is powered by a 3.5L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 29-mpg in the city and 34-mpg on the highway.