You're killing me.
EDIT: I think everyone really should
shop around, though. I've found a Thornton's station in Illinois nets me 38-39mpg per tank on 93 and then I fill up at the BP and my gas mileage instantly drops to 33mpg. It's happened more than once and I think it's more than just a coincidence / weather / driving style changes.
2012 FF Ti HB Kona Blue, DCT, Built 5/24/2011, 401A + Ti Handling Package, Parking Technology Package, Winter Package, Moonroof, and MFT w/NAV at v3.6 122k miles and counting...