Basic Tire/Wheel Size question? - TCCoA Forums
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post #1 of 4 (permalink) Old 05-01-2008, 04:57 PM Thread Starter
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Question Basic Tire/Wheel Size question?

Hey Im sure people have read over my stupid little thread about my plans or all that haha. Anyways I tried searching but nothing for my question really came up. So I'll ask here. Considering the stock size for the mn12 is 205/70/15. I am planning on putting on 18x9.5 Gt500 Replicas. With the larger I used this tire calculator

and the overall stock diameter of the wheel and tire is 26.3", with the new rim the closest diameter I can get to stock are: 25.7" with a 245/40/18 tire and 26.7" with a 245/45/18 tire.

My question is which would I be better off with? the smaller 245/40/18 or the slightly bigger 245/45/18? Of course tire inflation play a role too my main concern is keeping the speedo as accurate as possible. My gut is telling me that 245/45/18 is what I need to use cause I'd be going only a tiny fraction faster than what the speedo is telling me vs/ going slightly slower than what the speedo says? Or is the difference almost non existent with such a minor change?

What do you think?

PS: Much much would running the 245 vs 255 effect my mileage?

Last edited by punkrokr1701; 05-01-2008 at 04:58 PM. Reason: typo
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post #2 of 4 (permalink) Old 05-01-2008, 06:25 PM
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I would personally want the 255/45/18 (27" tall) for that 9.5" wide wheel.

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post #3 of 4 (permalink) Old 05-01-2008, 08:44 PM
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unless you own a 89-91 that came with white walls, the stock size is 215/70-15, or for sport/SC/M8, 225/60-16.

I would go for 255/45-18 as well. 10mm is not going to affect rolling resistance.

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post #4 of 4 (permalink) Old 05-01-2008, 09:37 PM Thread Starter
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oh im sorry that's what i found in a thread that seemed to "explain" everything about the mn12 tires/wheels, my bad, yeh i think 255/45 18 seems the best choice
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