I love my new truck, but am a bit dismayed at the gas milage. I thought it was a bit gas hungry, so this time I recorded milage at last fill up and just filled her up again. I did all city driving and am getting 9.47 mpg?!? I have been driving like an old lady for the most part I swear. It is due for its 30k checkup - what could I have them check for this? Note it has really lousy new tires from the dealer - Primewell P245/75R I know they are garbage, but could tired be contributing this much? I'm really depressed...