Sized between the Boeing 767-300ER and the Boeing 777-200, the 767-400ER features a lengthened fuselage; aerodynamic improvements, including additional wing span; increased takeoff weight capability; and an all-new main landing gear. The 767-400ER fuselage adds 11 feet (3.4 m) to the baseline 767-300 airframe, providing approximately 12 percent more seats -- accommodating 245 passengers in a three-class configuration and 304 passengers in a two-class configuration -- compared with 218 and 269, respectively, in the 767-300 version. The added seats reduce seat-mile costs relative to the 767-300ER, which already offers airlines the lowest operating costs in its class.