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Old 05-08-2020, 03:22 AM   #8476
wuuusaa
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Originally Posted by WhereAreYouScoobyDoo View Post
18x9.5 +38 w/ 275/35/18s


How much fender rolling and pulling did you have to do with getting those to fit?
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Old 05-09-2020, 09:26 PM   #8477
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Quote:
Originally Posted by wuuusaa View Post
How much fender rolling and pulling did you have to do with getting those to fit?
Not much surprisingly. Only rolled the rears, and no pulling!
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Old 05-14-2020, 02:03 PM   #8478
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So like many of you I have been through all 300+ pages of this thread. Pretty sure I am set on the following wheels,

ROTA DPT 18 X 9.5 +44 5x114 and I also plan on staying with the stock suspension. I am leaning pretty heavily towards a 265/35/18 tire, but want to ensure that the tire has no amount of stretch look to it.

Based on the offset I think I will be fine with poke, but based on some comments in the thread I worry that some tires will look narrower then others.

Any help would be great, summer tires only. I am using my OEM wheels as a winter set.
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Old 05-14-2020, 02:34 PM   #8479
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Quote:
Originally Posted by prerak77 View Post
So like many of you I have been through all 300+ pages of this thread. Pretty sure I am set on the following wheels,

ROTA DPT 18 X 9.5 +44 5x114 and I also plan on staying with the stock suspension. I am leaning pretty heavily towards a 265/35/18 tire, but want to ensure that the tire has no amount of stretch look to it.

Based on the offset I think I will be fine with poke, but based on some comments in the thread I worry that some tires will look narrower then others.

Any help would be great, summer tires only. I am using my OEM wheels as a winter set.
why not 255? thats not stretched on a 9.5 wheel
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Old 05-14-2020, 03:56 PM   #8480
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Originally Posted by standardtranny View Post
why not 255? thats not stretched on a 9.5 wheel
That is a possibility, but basing the 265 on giving more rubber, or a more meaty look. Also when I put in the numbers on willtheyfit.com I get this for the arch gap loss.

For 255 = -3.8mm
For 265 = -0.3mm

Which I believe equals, more negative is more gap.
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Old 05-15-2020, 02:45 AM   #8481
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Default Enkei TSR-X

18 x 9.5 +38, with 245/40r18. Stock suspension for now.

https://imgur.com/a/eCdD35E
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Old 05-15-2020, 09:00 AM   #8482
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"Stretch" based only on appearance is too subject to opinion . . . almost meaningless in some cases.

I'll look at the rest later, but for now, the plot shown on "willtheyfit" isn't good enough to be of much use. I'll give you a much better one that shows (approximately) the curvatures in the sidewalls.


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Last edited by Norm Peterson; 05-15-2020 at 11:13 AM.
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Old 05-15-2020, 11:33 AM   #8483
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Here's a better view of what they'd look like, each compared to the 18" OE WRX wheel and tire package. The OE 245/40's (black traces) are on their "measuring width" wheels, which is really the best reference point for 'stretch' or 'pinch'. Sidewalls on the 265/35 will be just outside the wheel flange, about half as much as the OE wheel/tire combination. Sidewalls for the 255/35 will be very close to flush with the wheel flange. Your call.






In terms of load capacity at any reasonable inflation pressure, the 265 tire would be a better match to the WRX and its recommended inflation pressures.


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Last edited by Norm Peterson; 05-15-2020 at 11:42 AM.
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Old 05-15-2020, 03:58 PM   #8484
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Quote:
Originally Posted by Norm Peterson View Post
Here's a better view of what they'd look like, each compared to the 18" OE WRX wheel and tire package. The OE 245/40's (black traces) are on their "measuring width" wheels, which is really the best reference point for 'stretch' or 'pinch'. Sidewalls on the 265/35 will be just outside the wheel flange, about half as much as the OE wheel/tire combination. Sidewalls for the 255/35 will be very close to flush with the wheel flange. Your call.






In terms of load capacity at any reasonable inflation pressure, the 265 tire would be a better match to the WRX and its recommended inflation pressures.


Norm
This is very helpful in regards to which tire size to go with. Hope whichever manufacturer I go with doesn't run too narrow in that size.
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Old 05-16-2020, 08:10 AM   #8485
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Quote:
Originally Posted by prerak77 View Post
This is very helpful in regards to which tire size to go with. Hope whichever manufacturer I go with doesn't run too narrow in that size.
Tire Rack and others provide pages of tire specs including tire section widths. The tire section widths in those tables are as measured on the tire size's "measuring width" wheel and can be compared to identify the tires that run narrower than others.

All tires gain about 0.4" (10mm) section width per inch of added rim width, so a tire that's relatively narrow on its measuring width wheel will still be relatively narrow when mounted on a wider rim.


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Old 05-31-2020, 11:46 AM   #8486
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Quote:
Originally Posted by WhereAreYouScoobyDoo View Post
18x9.5 +38 w/ 275/35/18s


Sorry if I missed it but what wheels are these?
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Old 06-01-2020, 08:27 AM   #8487
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Sorry if I missed it but what wheels are these?
Gramlight 57xtreme or avid av20.
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Old 06-01-2020, 10:15 PM   #8488
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Thanks!
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Old 06-05-2020, 06:03 PM   #8489
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@Norm, are all your plots done using just Excel with custom formulas?
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Old 06-06-2020, 09:21 AM   #8490
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Basically, yes. The sidewall shape is from two curve fits, one for the upper sidewall, one for the lower, with an iterated macro solution. It's not perfect by any means (I don't think it handles cases where the tires are stretched much past max-recommended very well, not that anybody intentionally doing that is going to care what my plots would look like anyway).

There's even two slightly different spreadsheets. One uses the nominal tire size for everything, and the other allows you to input actual dimensions. And there is a bit more going on in both of those workbooks than just the development of the plots I've been posting.



Any more, the only things I do to those sheets is occasionally add a line or two to the database of tire sizes vs min/measuring/max rim widths. Though on looking closer I might have a text cell that could stand some editing (one of the reasons I don't make sheets like this readily available is that there's no easy way for me to get them peer-reviewed to catch little things like what I think I'm just seeing in this one now).

For me, it was a great move by NASIOC to put up their own image hosting. I'd never used a 3rd party hosting service, and with what p'bucket and imgur have done I'm really glad that I never had used them.


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Last edited by Norm Peterson; 06-06-2020 at 09:39 AM.
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Old 06-07-2020, 12:57 PM   #8491
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Advan RG III 19x8.5 +45 stock Yokohama tires


Last edited by murrdogg24; 06-07-2020 at 01:02 PM.
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Old 06-07-2020, 01:01 PM   #8492
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18x9.5 +38 TE37 Saga - 265/35/18 Indy 500

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Old 06-08-2020, 11:31 PM   #8493
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Finally got some decent coilovers...

HKS Hipermax GT IV
18x9 +35 Advan RZ
245/40/18
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Old 06-11-2020, 12:25 PM   #8494
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Quote:
Originally Posted by PointNShoot24 View Post
Finally got some decent coilovers...

HKS Hipermax GT IV
18x9 +35 Advan RZ
245/40/18
Looks really good. What is the side profile like? Are they pretty flush to the fenders?
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Old 06-12-2020, 01:54 PM   #8495
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  • 18x9.5 +42 matte black
  • General G-Max RS - 265/35/18
  • Stock suspension


[/IMG]
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Old 06-15-2020, 03:25 AM   #8496
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Originally Posted by absubie View Post
Looks really good. What is the side profile like? Are they pretty flush to the fenders?
The rear is but the front has about -2.3 camber so it tucks in a little.
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Old 06-27-2020, 06:19 PM   #8497
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Wedssport 18x9,5 et39 + 255/35 r18

It is for sale, czech republic - 1200euro



Last edited by racingforum.cz; 06-27-2020 at 06:28 PM.
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Old 06-29-2020, 06:22 PM   #8498
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do you have anybody OZ ultraleggera or superleggera 18x8 et48 ?
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Old 06-29-2020, 11:28 PM   #8499
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Default can I ask about stock tirea here?

I didn't see a stickied "what tires do you run on stock wheels" thread so figured I'd ask here. I am getting some Michelin Pilot Sport A/S 3+ tires. This is on a stock 17 wrx premium, so 18x8.5 wheels. Looking at 255/40R18's or 255/35R18's but the 40 series tire is an SL load index tire and the 35 series is an XL which is supposedly reinforced on the shoulders and should provide stiffer/better handling. Is there a problem running an SL rated tire on these? Most sites tire notes say XL/XR required. The stock Dunlop were XL. The car is my wife's daily but is also our sporty weekend fun car. Other than sidewall height, how much weight should I put on the SL vs XL load rating? The worn out Dunlops gvie a lot of feedback and noise so either one should ride better, but I imagine the 40 series tire will be a more comfortable tire. I just don't want to get an SL tire where an XL should be used, even if it means going to the 35 series tire. Would I even notice a difference between the three in aggressive driving?
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Old 06-30-2020, 10:22 AM   #8500
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You have to look at more than just 'XL' and 'SL'. Basically, what you need to be doing is matching the rated load of your OE tires at their recommended inflation pressures. For the 2015-up WRX, I think the OE tires are 245/40-18, 97 in XL, and the inflation pressures are 33/32 psi.

After that it gets a little more complicated. The 255/40-18 is a 95 in SL, which actually corresponds to a 99 in XL (larger than OE). The 255/35 is a 94 in XL and is a slightly smaller tire than OE in terms of load capacity. In either case, you'd want to set inflation pressures slightly different from Subaru's 33/32. You could actually drop about 2 psi off of the door sticker number for the 255/40's, but you'd have to add about 4 psi for the 255/35's. Three load index numbers worth of correction is as far as I'm normally willing to consider.

Reinforcement is more for the XL tires being rated to 42 psi vs the SL tires to only 36 psi. I suspect any handling benefit would be mostly incidental.


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