I have a 2002 Ford taurus with the 3.0 duratec & 16,000. yes 16,000 original miles. the car was my grandfathers and it sat in a garage for around 2 years with only being started on occasion. Ive started driving the car and have been getting awful gas mileage 16-17 mpg. the window sticker rates it as getting 20-27. I don't drive the car too hard, or carry a heavy load, and i make sure all of my tires are inflated properly. What can be the causes of my car getting bad gas mileage and would it be fairly inexpensive to get it fixed if their is a problem?