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Location: Gold Coast, QLD
Registered: April 2004
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Re: Celica offset?
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Thu, 24 February 2005 23:21

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Yes offset does make a difference - too much and your tyre might rub on the strut, too little and it might rub on the guard. Going to a wider rim will also add to these potential problems.
If you've googled and searched, then you probably know that the offset is the distance from the mounting surface of the rim to the rim centreline. Here's a diagram that explains it quite well:

All FWD Celicas have an offset of +39. If you go to a higher positive offset (like the +50 you are considering) then it will move the inner sidewall 11mm (50-39) closer to the struts. And going to a wider rim will move it even closer again. Of course, going to a smaller positive offset (or even a negative one) will have the opposite effect & cause potential rubbing issues with the guard instead.
The other thing that offset will affect is the track width (the distance across an axle line from one rim centreline to the other). Whatever change in offset you make, the track width will alter by double that amount (since it is performed on both sides of the vehicle). Using the example of going to a +50 offset again, your track width will now be 22mm narrower than before. This is where you need to check your state regs carefully and make sure you are still legal. In QLD for instance you are allowed to increase your track by up to 26mm (ie 13mm per side), but you are not allowed to reduce it at all. (And why would you want to anyway, tyres sitting further under the guards don't look as good!) So this means you could fit rims with an offset up to 13mm less than 39 and be OK, but fitting rims with an offset greater than 39 would decrease your track width and be illegal.
I fitted 7th gen Celica SX rims (15x6.5", 205/55 rubber) to my ST162, so the offset was the same and was not a problem. However the extra half an inch rim width did mean that the front tyres did rub the guards during hard cornering - even with no change in offset. I rolled the guards and have had no problems since then. I think the best advice is to keep the offset as close to stock as possible, and not go over!
Sorry for the wordy post, hope it helps.
-Matt
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| Subject | Poster | Date |
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Celica offset?
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Blah_00 | Thu, 24 February 2005 15:36 |
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Re: Celica offset?
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Rainey | Thu, 24 February 2005 23:04 |
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Re: Celica offset?
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matt86sx | Thu, 24 February 2005 23:21 |
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Re: Celica offset?
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Blah_00 | Fri, 25 February 2005 14:21 |