The 2012 Buick Regal is available as a 4-door, 5-seat sedan. Starting at $27,055, the 2012 Buick Regal Base is powered by a 2.4L , 4 -cylinder engine mated to an automatic transmission that returns an EPA estimated 19-mpg in the city and 31-mpg on the highway. The top of the line 2012BuickRegalGS , priced at $ 34,835 , is powered by a 2.0L , 4 - cylinder engine mated to a manual transmission that returns an EPA estimated 19-mpg in the city and 27-mpg on the highway.