one thing i know for sure is that if i use anything OTHER than shell gas i only get from 250 -270 miles on a full tank and my light comes on i know it takes almost 12 gallons to fill, if i am not mistaken our tanks are 14 gal? however when i use shell gas i get more miles on a full tank i get anywhere from 320-330 miles as i get to a half tank i am well past the 150 mile mark, but i goose it from time to time when i reach the expressway or when the open road oportunity arises, and i give myself like almost 1-2 minute cool down time as well with the a/c on thru all of this, also i noticed that my car seems to run way better on shell gas than any other, but i wish we had Sunoco ultra 94 here, Sunoco's down here only go to 93 octane.