I just bought a Z71 5.3 liter. I guess I had a dream that I could get at least 13-14 average around town. I just did the math at the last fill up and it is reading around 11.6 MPG. My wife is driving all city about 16 miles to work total. Does this seem right? I am not running E85. I drove it home from the dealership I bought it at and was getting around 17 MPG. It has 57000 miles on it.