GM developed its Hummer EV in 20 months. It wants that speed to be routine.

GM is racing to cut new-model development to about two years (vs. the typical 4–6), pointing to the GMC Hummer EV's 20‑month build as proof it can be done.
The company is using AI, simulation and decades of engineering data to virtual-test handling, crashes, cooling and more — so physical prototypes are mainly confirmations.
The urgency comes from industry pressures — sluggish EV demand, shifting tariffs and regulations, and fast-moving, lower‑cost competition from China.