Detroit to Denver - One Way

I am leaving this week from Detroit Metro Area to Denver. Pretty much a straight shot with short stops for food and fuel. If the weather is lousy then an overnight is in order, usually Iowa with a stretch run to Denver. I am leaving between the 23rd and the 26th of August. I am flexible on the dates. Gas money is a consideration for your ride along. Big car, I mean BIG car ... Buick. But the fuel mileage is 27 MPG on the highway. Room for your stuff and more but absolutely no pets in my car. Don't ask.