Nio has concluded winter testing of its upcoming ES9, the company’s largest and most expensive SUV, as the Shanghai-based EV maker prepares for an April 10 launch event. “ES9 winter testing 2026. Mission accomplished,” Nio principal chief engineer Danilo Teobaldi wrote on LinkedIn Thursday while sharing images from the testing campaign. The engineering team tested the model in Yakeshi, a city in the Hulun Buir region of north China’s Inner Mongolia autonomous region that serves as a benchmark base for automotive winter testing in China. The ES9 is one of three large SUVs the Nio Group — which includes the Nio, Firefly, and Onvo brands — is launching this year in China.