One of the Gripen NG's key sales points is range. Saab says the fighter can fly 1,300km with six air to air missiles, loiter 30min and return to base. It's hard to make a direct comparison to the F-35 since performance specifications with external stores are not publicly listed. Using only internal fuel and weapons, the F-35A is designed to fly 1,093km with up to four air-to-air missiles and return to base.
Massive fuel tanks allow Saab to achieve the range goal for the Gripen NG. Saab has now tested the 50% larger, 450gal fuel tanks in flight, as the video above clearly shows.