The 2001 Mercury Grand Marquis is available as a 4-door, 5-seat sedan. Starting at $23,105, the 2001 Mercury Grand Marquis GS is powered by a 4.6L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 25-mpg on the highway. The top of the line 2001 Mercury Grand Marquis LS, priced at $25,005, is powered by a 4.6L, 8-cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 25-mpg on the highway.