I bought my 2002 WRX brand new 4 years ago. About a year ago, my gas mileage dropped off tremendously. It did not coincide with anything done to the car and it happended fairly quickly. I have no after market mods... I drive all highway miles-- 200 miles to and from work on the interstate. I am getting about 19 to 21 MPG. I used to get much more than that, I'm not sure exactly what I used to get, but I know that when I've driven to Florida and back from Connecticut I was probably going almost 400 miles without filling up. Now I'm lucky if I get 280 miles (all highway going 65 MPH!). I've brought it to 3 separate mechanics and the Subaru dealership (I was desperate)---had every diagnostic test done, changed filters, adjusted fuel trim, etc etc. Every body is stumped, including myself! Has anybody had this problem or have any suggestions? Thanks!