Hey all i have a question i hope someone can answer
i just bought a 3 06 and it came with 4" ranch lift and the tires and rime are just way to big im wanting to go to 17" rimes but because of the lift i need to figure out the offset i was told buy a local tire shop that i need -12 offset to clear the lift in the front what do you all think of what size rim and tire combo i should go with to still have the cool factor lol and not looking like a 3 with 4 balloons attached to all 4 corners thanks for your time .....

 

what size are the tires that are on it now? 16 or 17" rims should be fine if you want more tire than rim, which in my opinion is how a hummer should be, esp if you go wheeling.... other than that, the 315's are about the biggest that should be on an H3, as far as proportions go.. i do think that most owners with the 3" or 4" lift run the 315's on them as well. hope that helps...

 

You want 4 1/2" backspace on your wheels. And rule of thumb if you wheel your truck is, tire diameter should be at least 2x the wheel diameter so you have enough sidewalk for give

 

Got bigger pics of the H3 then the ones in your avatar? What size are your current tires? I would look for a 17x9" with a 4.5" back spacing and go with a 35x12.50R17 tire. You can't choice the wheel based sole offset because the offset changes with rim width. You need a wheel with a 4.5" or less back spacing to clear the steering knuckle and upper control arm.

 

thanks for the replies all the tires that r on it r 355/65/18 they were their when i bought it last week today i talked to a couple tire shops and they said i need -12 off set is this the same as 41/2

 

larger pics in gallery

 

No, it is not the same.

Backspace is the distance from a wheel's mounting surface to the back edge of the wheel in inches. "Back" means the brake side of the wheel.

Offset measures the distance from the mounting surface of the wheel to the centerline of the wheel, and it is indicated in millimeters.

If the mounting surface is located closer to the street side of a wheel, then the offset is positive. If it is located closer to the brake side of wheel, then the offset is negative. If it is in line with the center of the wheel, then the offset is zero.

Examples:
The centerline of a 10-inch-wide wheel is at five inches.
If the wheel has a 6-inch backspace, then the offset is positive.
If the wheel has a 4 inch backspace, then the offset is negative.

The centerline of a 8-inch-wide wheel is at four inches.
If the wheel has a 6-inch backspace, then the offset is positive.
If the wheel has a 4 inch backspace, then the offset is zero.

Offset changes with wheel width, so the more important factor is Backspace.
Backspace is a constant regardless of the wheel width.

If you don't have the correct Backspace, then a wheel is more likely to rub the brakes or the suspension components.

The Rancho lift requires wheels to be at least 17" dia. & have 4-1/2" backspace to clear the brake calipers.
The Offset will be different based on 8", 9" or 10" wide wheels

 

Nice post John! I think that bout covers it :P

 

As I stated earlier and Bunger explained in detail, you want to choice a wheel based on back spacing and not off set. The 325/65R18 Kumho Road Venture AT you have are ~35x13.50.

 

The Rancho lift requires a 16, 17, or 18" with a 4.5" or less back spacing or a 20"+ wheel with a 5" or less back spacing. The reason for the back spacing is to clear the longer steering knuckle included with the kit and the upper control arm. Some 16" wheels will have brake caliper clearance issues but some 16" wheels will work with the Rancho kit.

*edit,
here is a picture borrowed from Mr. CJ Wilson (4speedfunk/Thorparts) of the clearance issue