It is difficult to believe that a Tahoe 350 can get 18mpg in the city. I get 14mpg out of mine, and I consider myself lucky, as I know many people in the 10-12 range. I only get 18mpg out of my Jeep with an I-6, and about 10mpg out of my CJ-5 with a 350.
I drive with a light foot, only city...