Speed and range are key parameters for those who use business jets, and the new Gulfstream G650ER, which first reached customers ahead of schedule in mid-November, aims to deliver on both. Among the new breed of large-cabin ultralong-range business jets, the extended-range version of the top-of-the-line Gulfstream G650 can carry an extra 4,000 pounds of fuel, thanks to an advanced fuel-quantity monitoring system and other upgrades, increasing the range by 575 miles—enough to cruise 8,600 miles, connecting New …