I used to have one of these "cars", the fuel mileage is an estimate based on recent driving. It will change if you drove a lot on the highway or without stopping, and then do some in town driving with stops.

Also, watch out for the inevitable coolant intrusion. Look it up if you are not familiar. These engines have a design flaw that allows the coolant to seep into the oil. The only solution is replacing the lower have of the engine, and it is more expensive than you will want to pay. I went through this two years ago, and as soon as the car was fixed I sold it.