Gulfstream announced performance enhancements for both aircraft in October 2017. The G500 will fly 5,200 nautical miles at Mach 0.85 or 4,400 nm at Mach 0.90, while the G600 can travel 6,500 nm at Mach 0.85 and 5,100 nm at Mach 0.90. The maximum operating speed for both aircraft is Mach 0.925. These performance enhancements have not altered Gulfstream’s delivery timetable. Both aircraft will enter service this year, the company says.