Ok, most of you probrably wont believe me, but the a/c in my 91 deville deflated during the winter due to a leak when the service station replaced a part, and because there was no refridgerant in the system it caused poor gas milage some how. I took it in to a dealer and they told me i need to fix the a/c. I didnt believe it either, but as soon as i filled the system up, the milage went back to normal. Anyone else experienced this?? I still cant hardly believe that was the case.