2024 SILVERADO EV aero estimate
 

Using available data provided from GM, and estimating frontal area @ 36.4-sq-ft, an EPA dyno test weight of 8,300-pounds, and rolling resistance coefficient similar to the RIVIAN pickup; and estimated 63.5 mpg HWY, at 62-mph, Cd 0.3614 falls out of the math.
This would constitute 20.478- hp R-R, 21.404-hp aero, for a Road Load= 41.883-hp @ 62-mph ( 100-km/h ), @ 95% mechanical efficiency.
5.9338-gallons-e, HWY range 377.1-miles.
I look forward to official values.