The 2005 Mercury Mariner is available as a 4-door, 5-seat sport utility. Starting at $21,425, the 2005 Mercury Mariner Convenience (100A) FWD is powered by a 2.3L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 22-mpg in the city and 26-mpg on the highway. The top of the line 2005MercuryMarinerPremier (330A) 4x4 , priced at $ 26,785 , is powered by a 3.0L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 18-mpg in the city and 23-mpg on the highway.