I understand your delima, and the fact that some of the figures you've heard seem hard to believe. I can assure you they are accurate. I bought my 1996 LS, 20 months ago with 82K on the odometer. I have done a few road trips at different times of the year, including a D.C. to Miami last fall. With the cruise set at 76-78mph, and the A/C on, I get an eerily consistant 27.33 mpg.* The vehicle is, without doubt, an outstanding used car value in it's segment. I now have 102k, and have only paid for oil and tires(all four wore down completely evenly). I am very happy with this vehicle.
*Keep in mind it does require premium fuel.