I ordered an Edge Evolution for my tahoe, I have a 2008 PPV. My wife, the baby and I went to Littlerock (from Memphis) over the weekend. I set the cruise between 75-85 mph the whole way and got an average of 17.5 MPG. I will try the power mode but my main reason for buying the programmer is to help my MPG so I will set it to economy mode after I play a bit. I have read some getting 20-22 mpg on the freeway. Any one have one and keep up with their MPG?