The 2016 Cadillac XTS is available as a 4-door, 5-seat sedan. Starting at $45,295, the 2016 Cadillac XTS Standard FWD Sedan is powered by a 3.6L , 6 -cylinder engine that returns an EPA estimated 18-mpg in the city and 28-mpg on the highway. The top of the line 2016CadillacXTSB05 Armored FWD Professional , priced at $ 50,095 , 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.