It has to be something in the gasoline here in TX, since I drove to SC a few months ago with my '14 Tundra, and when I filled up in another state my mileage went up to 21.5 mpg, and when I drove to Ohio, I averaged over 19 with my EMC engine and all my equipment, engine stand, in the truck. I went to Colorado and averaged 22, but come back into TX and the next tank of gas drops to 17.5 and stays there. When I checked the average on the display, it was 17.0 here around town with mixed road driving over months. Really disappointing to go out of state and mileage jumps up even with my wife's car. I have tried Shell, Exxon, Valero, Standard, HEB, Wall Mart, and even some truck stop fuel with similar results. We must get the swill of leftover fuel here. Joe-JDC