The 2013 Cadillac XTS is available as a 4-door, 5-seat sedan. Starting at $44,075, the 2013 Cadillac XTS Base FWD Sedan is powered by a 3.6L , 6 -cylinder engine mated to an automatic transmission that returns an EPA estimated 17-mpg in the city and 28-mpg on the highway. The top of the line 2013CadillacXTSB05 Armored FWD Professional , priced at $ 49,575 , is powered by a 3.6L , 6 - cylinder engine that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway.