public class EighteenWheeler implements MotorVehicle
{
  public EighteenWheeler()
  {
    mpg = 8.0;
    tankCapacity = 250.0;
  }

  public double getMPG()
  {
    return mpg;
  }

  public double getTankCapacity()
  {
    return tankCapacity;
  }

  private double mpg;
  private double tankCapacity;
}