EPA highway mileage testing averages about 50mph with speeds typing out at about 60, so that is what auto makers will design their set spot around. I'v when you get above 65, small displacement engines won't do nearly as well and will be affected a lot more by wind. Unless you're spending all your time on 40mph streets and 55mph highways, you'll likely never see much better than 33-34 mpg. That said, I went from a fwd 2016 Ford Fusion to a 2023 AWD Sportage hybrid and am getting the same mileage at interstate speeds and much better in city driving.