The 2010 Jaguar XJ is available as a 4-door, 5-seat sedan. Starting at $71,650, the 2010 Jaguar XJ Base is powered by a 5.0L , 8 -cylinder engine mated to an automatic transmission that returns an EPA estimated 16-mpg in the city and 23-mpg on the highway. The top of the line 2010JaguarXJBase , priced at $ 111,150 , is powered by a 5.0L , 8 - cylinder engine mated to an automatic transmission that returns an EPA estimated 15-mpg in the city and 21-mpg on the highway.