They look to be Style 131 on the following link, however, when you click the image of that wheel another pops up. Not sure why there's a glitch, but that guide is awesome!
18 x 8.5" Non-sport Package wheel
Xoutpost.com - Xoutpost.com wheels.htm
EDIT: They are Style 153 Plus-size replicas as other posters have noted. The wheel style guide I linked to has Style 131 and 153 pix switched. Sorry for any confusion.