Prospective Buyer

[f5fstop]

My opinion would have been that a manual would have made it since I got the impression from truck trend that the drive had a problem finding the right gear ("here, the manual transmission made it difficult to quickly find the right gear"). If you can't find the gear you will roll back, and launcing on a hill is harder than with an auto. The auto would downshift to the right gear.
Plenty of test vehicles climbed similar if not steeper grades, and I believe there have been some posts here of non-GM employees climbing similar grades with no problems.
In Sept. and Dec. I did some 6% and greater grades in Eastern TN (I believe the greatest was about 8.5%), not on an interstate but on some mountain roads, and had no problems keeping it up to 65-70...yes it does downshift, but I kept it in 3rd while climbing the roads. You can't pass a heavy truck clocking around at 50 when going up one of these grades, even in a long straight portion of the road, but flat or downhill was no problem.
I have not tried the Bridgestones on Rock, but in gravel/loose dirt and on pavement, I have no complaints. But the majority of those GM test vehicles used the Bridgestones and they seemed to have no problems (other than ripping off the rear license plate).
Hopefully, some from you state or other western states will post some comments.