The 747-400 is an improved model with increased range. It has wingtip extensions of 6 ft (1.8 m) and winglets of 6 ft (1.8 m), which improve the type's fuel efficiency by four percent compared to previous 747 versions.[173] The 747-400 introduced a new glass cockpit designed for a flight crew of two instead of three, with a reduction in the number of dials, gauges and knobs from 971 to 365 through the use of electronics. The type also features tail fuel tanks, revised engines, and a new interior.
