The 2011 Buick Lucerne is available as a 4-door, 5-seat sedan. Starting at $29,730, the 2011 Buick Lucerne CX is powered by a 3.9L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 27-mpg on the highway. The top of the line 2011BuickLucerneSuper , priced at $ 44,460 , is powered by a 4.6L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 23-mpg on the highway.