We have just driven three times from Kansas City to Wichita, and back, about 450 miles each time, the average mileage worked out to be 26.5mpg.. however I would recommend "Flying J " gas as its filtered twice and at Emporia its an amazing 179.9 a gallon for 91 oct. we get 10% better mileage with it, we regularly travel across to Oregon and down to Florida..and always search out the Flying J's