Update: now I am averaging 13 city. I took it out on a two hundred mile stretch recently. Going out I got 19.9 Hwy. Coming back I was pulling the small uhaul and got 13.8, but I had it trailer mode the whole way. So far I'm happy. My 08 Envoy was smaller, had the straight six 4.2l) and got worse fuel economy. So, Tahoe rules the day. I'm still trying to squeeze a bit more economy out of it. New set of Michelin LTX's coming soon. Front end getting aligned tomorrow. O2 and mass air flow sensors next.