The 2018 Buick LaCrosse is available as a 4-door, 5-seat sedan. Starting at $29,565, the 2018 Buick LaCrosse Base FWD is powered by a 2.5L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 25-mpg in the city and 35-mpg on the highway. The top of the line 2018BuickLaCrosseEssence AWD , priced at $ 41,070 , is powered by a 3.6L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 20-mpg in the city and 29-mpg on the highway.