Given that the weight is at its maximum, the displacement and the cylinders are higher as well. The horsepower is toward the higher end which results in a lower acceleration time. The mileage in turn is lower and results towards the lower end.
A higher horsepower results in more displacement, higher weight, and a higher number of cylinders. The acceleration is thus quicker and has a quicker 0-60 mph time. This results in a lower mileage and leans towards the older set of cars.
One of the main trends that is visible is that a higher cylinder car has more horsepower, a higher weight and displacement and gives a lower milage.