(Related - Bugatti Chiron and Vision GT Sold to this Guy for How Much?)
In the video's description, Bugatti notes: "More than 30 test vehicles were or still are in use, including the four vehicles that the Bugatti engineers took to the US this summer to perform endurance tests in the scorching heat of Death Valley and other American deserts." They also say that they spent four and a half weeks testing the car, driving 21,747 miles in 124.7 F° weather.
Check out the video below to see the Chiron being tested for yourself.