The new version increases the maximum takeoff weight of the King Air by 385 pounds, while adding only 35 pounds to the empty weight. That's an increase of 350 pounds in useful load. That provides 737 pounds of cabin payload, not counting the weight of the single required pilot, with full fuel. The x version can carry four passengers 195 nm farther than the previous 90GTi airplane at high speed cruise. The winglets make the wing fly as though it were longer and is thus more efficient in climb and cruise, so the extra fuel allowed by the increase takeoff weight goes farther.