Not with leaked information
this suggest 0.55 classic brick silverado
this suggest 0.48..2003-2005
this suggest 0.49 for 2006(HD hood)
ACTUAL drag coefficient of 0.412 for the 2007-2013 Silverado
this suggest '14,15 has .40
this suggest 16-19 are .38-.36
just estimation based off of the leaked "actual" 2007-13 DATA