I am looking for a new set or rims. I have stock 20's on my leveled 05 4x4 with 35 x 12.5 terra grapplers. So to stop the rubbing issues I would need 1.5" spacers so I have been told. With not using spacers I would need 1.5" less backspacing on new rims I think. So most rims are 4.5 back space which is a easy decison so I gain a inch wider there. I want a 20 x 10 rim but not sure of the off set. Can someone point me in the right direction I am sure someone here has a similiar setup. I just dont want to rub, but be wide enought to fill pocket style fender flares. Thnaks for the help.

 

The factory 20" Ram wheels have a +19mm offset. That means it has a backspacing of 5.75" on a 9" wide wheel. You'll want a wheel that has a 4.5" backspacing which is like putting a 1.25" spacer on the stock wheels. Doesn't matter if you want a 15" wide wheel, you'll still need that 4.5" backspacing to clear the inside. The lower the backspacing, the further out the fender the tire will stick. A 10" wide rim w/4.5" BS is gonna stick out like 3" from the factory fenders so even 2-1/2" flares there will be 1/2" sticking out.

 

So if 20 x 10 with a 4.5 BS would stick out 1/4 inch. would I be correct in saying I need 20 x 10 x 4.5 BS with a +10 offset to stay inside the fender flares and have enough clearance for inside wheel well?

 

Where are you getting the +10 from??? Offset is the deifference from the centerline of the wheeland the backside of the bolt face. Backspacing is the measurement from the backside of the bolt face to the inside outer edge of the wheel.
So, You want to order a 20x10" wheel with a 4.5" backspacing. Forget about the offset. If that's all they list(highly doubtful) then at 4.5" of backspacing the offset would actually be -25mm.