Mileage use in city and highway

What are we supposed to look at what the "book" says your mileage should be? Guess I will have to look for you~

...well it ain't too good...kinda an eye-opener~

21-23 MPG on Fuelly -- http://www.fuelly.com/car/jaguar/x-type

Depends what spark plugs and intake filteupgraded my sparks to nkg iridium xr and kn intake now I get 32 on da highwayand 19 city , but als depend on how u drive and motor oil too , castrol edge has done wonders for mt car.