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post #1 of 26 (permalink) Old 02-16-2010, 10:22 AM Thread Starter
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Questions About 18s

i have a set of 18" wheels that i want to put on my LT,the stock wheels are only 15s and some people are saying that i would have to calibrate the speedometer for those,but ive been reading a few posts on here and havnt seen where anyone has calibrated their cars for 18s and i was wondering if i would have to and if i did how would i do it? i was kinda thinking u wouldnt have to because the ABS wheel speed sencors would still read the same beacause the axel would still go the same,but then again those are for the ABS witch are breaks. but i also know that the engine will have to work alittle harder because of the little extra weght,so im confused,plz let me know

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Last edited by LT1R; 02-16-2010 at 10:21 AM.
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post #2 of 26 (permalink) Old 02-16-2010, 10:27 AM
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You wont have to do anything to the spedo. Ive got 18s and im fine...
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post #3 of 26 (permalink) Old 02-16-2010, 10:42 AM Thread Starter
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ok,thanks,i just wanted to make sure,and would u know where i could get a spare to match the 18s,cause id hate to b somewhere and have a flat and end up having 3 18" wheels with a little 15" doughnut on,lol

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post #4 of 26 (permalink) Old 02-16-2010, 10:46 AM
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i wouldnt worry about getting a spare. unless you really think your going to pop a tire
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post #5 of 26 (permalink) Old 02-16-2010, 10:48 AM Thread Starter
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i know,im just thinking of in case that would happen,because u really dont really know when u are going to get a flat unless ur trying to pop it
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post #6 of 26 (permalink) Old 02-16-2010, 10:50 AM
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yea and even if you do get a flat put a spare on til u get the tire fixed.
my sister had to do that. looked pretty funny because all the other rims were 18 and a little donut was on the one side
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post #7 of 26 (permalink) Old 02-16-2010, 10:53 AM
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The outside diameter is what has to stay the same, as long as that is within a reasonable limits, your speedo should be fine. But if you put over sized tires, like I did to my ranger, your speedo will need to be recalibrate to be accurate.

I don't see it causing any issues as long as you maintain your outer diameter.
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post #8 of 26 (permalink) Old 02-16-2010, 11:03 AM Thread Starter
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would 224/40 work then?
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post #9 of 26 (permalink) Old 02-16-2010, 11:08 AM
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Quote:
Originally Posted by LT1R View Post
would 224/40 work then?
Visit this page Tire size calculator

Put in your stock tire size, and it tells you the radius and diameter. Then use the other slot to adjust your rim to 18"s and your tire size to maintain the same diameter.

From there you can adjust the new tire ( for your 18's) to the height and width you want, and keeping the outer diameter the same. It might be a good idea to open up a tire site to make sure your size is a real size and is available.

From my quick looks early I wrote down 225/40 r18, which is what you were asking and I would lean towards yes, but always double check. I could be wrong!

Last edited by Adamseye; 02-16-2010 at 11:10 AM.
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post #10 of 26 (permalink) Old 02-16-2010, 12:58 PM
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225/40 is very close to the stock size. Well, as close as you are going to get with that width.

And Adamseye is right, as long as the overall diameter is close to the stock size, you should be fine.


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