My guess is that they're 9" wide given the offset (-12 is common for that width).
From DC website: http://www.discounttiredirect.com/direc ... &typ=Truck
Diameter 17.0”
Width 9.0”
Bolt Pattern 6-114.3mm
Offset -12
Finish MATTE BLACK/MACHINED LIP
Availability Low Stock
He hasn't posted in here in more than 2 years but hopefully he can chime in and verify.