Question on 20's and sidewall

cooltoy

Cool.

shurik355

Guys I don't know if you're aware of the fact that when the tires go wider the sidewall % gets taller. That's why if you look at our factory set up we have 245/45/19 front and 275/40/19 in the rear.

So my question was to people who understand tires very well, when I get to 295 width with 20" wheel, do i still go with 30mm sidewall or go down to 25mm?? At what point/width should the sidewall thickness should decrease???

Hope this makes sence.

cruzthepug

Actually on the 19's the tires are 245/40 and 275/35 but your exactly right.

245/40-19 is 26.7" tall
275/35-19 is 26.6"
305/30-19 is 26.3"

But the same width going up in sidewall ie 275/40-19 is 27.7" tall





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Rid3_FaM0uS

You pretty much answered your own question bud. The % of sidewall is just telling you your tire side wall is X number at 40% of 295mm. Yes you will always want to drop the sidewall size(in a normal case). To answer your question more specifically you need to make sure your front and rear tires do not exceed a 3% height difference or it will throw your abs/wheel speed sensors crazy in turn disabling the VDC. So make sure that when your sizing your fronts size them accordingly to your rear.

The only reason I didn't drop down to a 265 ish tire in the front is because they don't offer it for the radial tires I have and I wanted matching front and rear treads(picky yes, but it is what it is.)

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falconfixer

Those are drag radials? Look like S0-4s with those rain channels.

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kenchan

you have to calculate to get to the closest to stock total diameter.
ive noted several examples to cooltoy, check out the tread.

basically take the width (in mm) multiply by sidewall in percentage.
then take your wheel diameter multiply 25.4 to convert the diameter in mm.

then diameter + sidewall x2 = your total diameter. btw, use excel.

GL

Rid3_FaM0uS

Yes they are nitto drag radials.

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iCraigerz

Alright. So I ended up going with 20x9.5" (255/35/20) in the front & 20x11" (305/30/20) in the rear. I'll get the Swift springs and call it a day. I went with the F14's in the Red Velvet w/Silver Base-coat finish. The car is light silver. Thnx for all of your input.

Craig

shurik355

I think you should have gone with 305/25/20 in the rear instead of 30 side wall. Might be a little too tall with 305s?

Did you calculate it???

Radride

You are correct. Picking tires isn't rocket science. Obviously no one paid attention to my post about OD of the tires. Then people wonder why they rub...

If in doubt, go onto tire rack and pick a tire by size and go under the specs. It will tell you the OD of the tire you chose....

R.K.

iCraigerz

I had the guys at getyourwheels.com do that for me. I'm not saying they're right, but I hope so.

iCraigerz

What do you think R.K.?

Will they rub? I can still change the order as they're not shipping for another month or so.

The tires are 27.2" OD opposed to the stock 26.5". That's seven tenths of an inch difference. Whereas the 305/25/20 are 26" OD which is half an inch short of stock.

Also, I'm throwing the Swift R-Spec's on it as well so that'll lower me 1".

Thnx.

Radride

When I search 305/25/30's they are exactly the same size as OEM at 26.5":

http://www.tirerack.com/tires/tires....omCompare1=yes

Anytime you go taller than stock, you risk rubbing. Will it rub...I don't know.

Also, you better be running at least a 10" wide front to run 275's on it. Other wise they will bulge over and again have a chance to rub. I would also need to know the sizes and offsets of the wheels that you are getting.

R.K.

iCraigerz

Nah it's a 20x9.5 (255/35/20) in the front.


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Radride

Okay. Get the 265/30/20's that way the way the tire sits on the front wheel will be consistent with the rear wheel. Otherwise your front's will be slightly stretched but the rears will be square. Its up to you in the end.

R.K.