my truck is somewhat unique in comparison to the chevy / gmc 1500 lineup...
so far i havent been able to finda a published number specific to it.
the truck has a unique front bumper, arguably more aerodynamically friendly then a standard sierra, however it has a larger frontal area due to the rear wheel steering. i believe overall width is 4-6" more than standard, but GM did a nice job feathering the "hips" back into the truck.
ok... what you need to find the Cd
Truck is a 2002-2005 GMC Sierra Denali with Quadrasteer.
hope someone can find it