The 2009 Buick LaCrosse is available as a 4-door, 5-seat sedan. Starting at $25,640, the 2009 Buick LaCrosse CX is powered by a 3.8L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 28-mpg on the highway. The top of the line 2009BuickLaCrosseSuper , priced at $ 33,805 , is powered by a 5.3L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 24-mpg on the highway.