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Old 05-11-2006, 07:53 PM
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Question Question on mm offset?

I have read the above posts on putting ZO6 replicas on Camaros, l purchased two 18x9.5 and two 18x10.5, looks like if your mm offset is between 50 to 54mm and I run 285 35R 18 all the way around I will need no bfa mod. and will have no rubbing. My question is I looked on the back of the rims and they all say et53, is this the offset number I am looking for? Seller said these rims would fit a Camaro but was not sure of the mm offset number. Would these rims be a good setup, for some better traction on the street? Thanx for the input.
Old 05-12-2006, 12:39 AM
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Anyone, can someone help me out here.
Old 05-12-2006, 10:47 AM
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It probably is the offset if no other markings are on there other than the diameter and width of the rim.
Old 05-12-2006, 08:25 PM
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Tire shops I called said that it was not the offset number, but why plain as day would the rim have a marking reading et53 along with the 18x9.5 and 18x10.5 on the other rims.? I believe according to the top posts above 285 35R will be just fine with no rubbing or modifications needed.
Old 05-12-2006, 10:55 PM
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Why not just measure the backspace of the wheel. Why attempt to convert to offset. Offset is a funny thing. It is not measured the same way throughout the industry. Some measure offset at the bead surface, some use the overall width. Backspace is universally measured.

Also...these millimeter numbers, do you guys realize the small differences you're considering...you'd be hard pressed to notice these differences. The difference between the two numbers you references is 4mm, which is .157" slightly less then 3/16 of an inch! That amount varies easily between tire manufacture specs alone....

Food for thought.

Steve
Old 05-13-2006, 11:08 PM
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Are you telling me most likely the rims wheel fit with no modifications?
Old 05-14-2006, 09:32 AM
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I'm telling you by measuring the wheels backspace is going to be a much better way to compare to the typical wheels you see in the FAQ section. By considering one manufactures offset to another may not be a good comparison since offset isn't universally used in the same manner.

Also, don't be too concerned with whether or not a few milimeters will make a difference because it wont.

Since you already own the wheels, why not just put them on the car and see how you like them BEFORE you mount the tires.
Old 05-14-2006, 11:58 AM
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Okay, I will do that. I spoke to a tire shop,and they said there is a formula to figure out the offset of the rim. Measure the the rim across add one, then from there they weren't sure what number to divide into it.
Old 05-14-2006, 12:25 PM
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That's your best choice. You can use simple calculations to figure the offset...but the problems is as stated, some measure offset calculations from the bead surface, some from the outer most portion of the wheel. Since you don't know which company is reference what, the best option is to use backspace.

When I have a customer that asked to build a wheel for them and they give me a specific offset, I require them to tell me the actual backspace measurement they have so that we build it to the same backspace reference...not the offset since I do not know which way the manufacture is referencing their offset measurement...the outer-surface or the bead surface.




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