Please chime in if you have a heavy combination like I do (Automatic Transmission LTZ RS) and are not getting 45 MPG like some of these Eco guys. The best I can manage is high 20s average, even with a bone stock tune and 41 psi in all 4 tires. Some of the things that I know are hurting my #s are 1) we have the A/C running 100% of the time, it is waaay too hot without it, 2) Ambient temps are 90+ with high humidity which contributes to low oxygen content per air mass and timing being reduced, 3) Traffic jams / idling can sometimes sabotage a good trip, people really suck at driving here in Miami LOL. That being said, we are at sea level which is supposed to be good, and I am very light on the throttle as much as possible to save gas, other than a rare burst to 100 to pass a big truck that is throwing rocks or something. I can get 35+ MPG with the cruise control set to 70, but my overall is 30.5 MPG which is even 3 MPG optimistic according to Fuelly. So I was really wondering what some of you other Automatic fully loaded guys / gals are getting in crappy climates / conditions. My trans is not slipping at all. Thanks.