The 2005 Pontiac Montana is available as a 4-door, 7-seat extended passenger van. Starting at $26,040, the 2005 Pontiac Montana w/1SA is powered by a 3.4L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 26-mpg on the highway. The top of the line 2005PontiacMontanaw/1SE , priced at $ 30,420 , is powered by a 3.4L , 6 - cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 26-mpg on the highway.