The 2015 Lexus IS 350 is available as a 4-door, 5-seat sedan. Starting at $40,065, the 2015 Lexus IS 350 RWD is powered by a 3.5L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 28-mpg on the highway. The top of the line 2015 Lexus IS 350 AWD, priced at $42,300, is powered by a 3.5L, 6-cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 26-mpg on the highway.