Wheels Rules Question

markmerrill · **Joined:** Fri Apr 30, 2010 3:21 pm **Posts:** 48

Hi folks, I'm working on getting a new set of wheels and had a question about the rules:
The rules state:

Quote:

A. It is the same width as standard and as installed it does not have an offset
more than ±7.00 mm (±0.275”) from a standard wheel for the car. The
resultant change in track dimensions is allowed.
B. Wheel (rim) diameter may be increased or decreased 1” from the standard
part

OEM wheels for the 2016 Subaru WRX are either 17x8 55mm offset or 18x8.5 55mm offset

Can I get a wheel that is 18x8? or would it have to be 18x8.5? Would I want a wheel .5in thinner? I ask because... 18x8.5 with an offset close to 55mm is darn hard to find at a reasonable price. :-(

markmerrill · **Joined:** Fri Apr 30, 2010 3:21 pm **Posts:** 48

... and I immediately notice that I need to update my profile image because I no longer have the 'vette. /sigh

Chad Culbertson · **Posted:** Fri Mar 24, 2017 12:21 pm

I believe that if both wheels were available that year on your model then you could use the wider of the two, plus you have the ability to run +/- 1" diameter. You can also run +/- 7mm offset as well.

So far as I understand it, you could run 17x8.5, 17x8, 18x8, 18x8.5.

JasonWatts · **Posted:** Fri Mar 24, 2017 7:34 pm

Is this for stock class? I havent followed rules in a while, but I thought changing the features of a car unless specified had to be an all or nothing. EG if you upgrade the wrx to the wrx special edition you have to take ALL UPGRADES from the special of the SAME year, not a pick and choose.

I didnt follow the latest generation of the WRX, but I thought they all had 17in wheels? I know the WRX STI comes with 18's, but i dont think your upgrading your whole wrx to an STI. As I didnt follow, maybe there was some special model that came with the 18's?

If that's the case, then I believe you are limited to the 8in width, + or - an inch in diameter from 17.

markmerrill · **Joined:** Fri Apr 30, 2010 3:21 pm **Posts:** 48

I opted for a Premium 2016 which comes with 18x8.5 wheels. Tirerack also recognizes that as one of the standard sizes.

I had a friend whose car had different wheels on front and back and found that it was legal for him to use the larger of the two sizes all the way 'round. Not saying that I know for a fact that's right... but you could see why I'd be asking for clarification.

markmerrill · **Joined:** Fri Apr 30, 2010 3:21 pm **Posts:** 48

And yes, this is for Street class.

Arthur McDonald · **Joined:** Fri Aug 29, 2003 1:54 am **Posts:** 2052

If the option package that your car was built with only came with 18x8.5's then that's your wheel width. You can go up or down 1" on the diameter.

Chad Culbertson · **Posted:** Sat Mar 25, 2017 11:27 am

markmerrill wrote:

I opted for a Premium 2016 which comes with 18x8.5 wheels. Tirerack also recognizes that as one of the standard sizes.

I had a friend whose car had different wheels on front and back and found that it was legal for him to use the larger of the two sizes all the way 'round. Not saying that I know for a fact that's right... but you could see why I'd be asking for clarification.

I did that for the Camaro, rear wheels were 20x9, fronts were 20x8s. I bought two more rear 20x9s and put them on the front. Granted I was running CAM due to other changes but to my understanding that was legal to do.

Sounds like technically your stuck with 8.5s but I seriously doubt anybody here is going to care if you went down to a 8", you're technically giving yourself a disadvantage that way anyway and we're not a SCCA club.

JasonWatts · **Posted:** Sat Mar 25, 2017 1:53 pm

Chad Culbertson wrote:

markmerrill wrote:

I opted for a Premium 2016 which comes with 18x8.5 wheels. Tirerack also recognizes that as one of the standard sizes.

I had a friend whose car had different wheels on front and back and found that it was legal for him to use the larger of the two sizes all the way 'round. Not saying that I know for a fact that's right... but you could see why I'd be asking for clarification.

I did that for the Camaro, rear wheels were 20x9, fronts were 20x8s. I bought two more rear 20x9s and put them on the front. Granted I was running CAM due to other changes but to my understanding that was legal to do.

Sounds like technically your stuck with 8.5s but I seriously doubt anybody here is going to care if you went down to a 8", you're technically giving yourself a disadvantage that way anyway and we're not a SCCA club.

Is it really a disadvantage? the .5 less is less rotational mass and will help with acceleration :sing:

. At our level, most dont really care unless your constantly placing 1st in class and they want to nitpick.

Chad your change in rules is allowed by CAM. In street you have to stay within your package. If he wants to run the 8.0, he has to downgrade the whole car to the standard edition to run them.

Chad Culbertson · **Posted:** Sun Mar 26, 2017 7:58 pm

Pretty sure even street class allows you to run a rear wheel up front (assuming it was a staggered setup) so long as you stay within the diameter and offset limits.

Chuck Branscomb · **Posted:** Mon Mar 27, 2017 9:13 am

Chad Culbertson wrote:

Pretty sure even street class allows you to run a rear wheel up front (assuming it was a staggered setup) so long as you stay within the diameter and offset limits.

I wish that was the case, but it's not. You are required to run stock, staggered wheel widths in street class. Many run square tire setups on the staggered wheel widths which of course is legal.

Steven Carter · **Posted:** Mon Mar 27, 2017 2:01 pm

Don't/can't go down in width. IMO +1 wheel diameter just makes tires more expensive unless you really need a tire diameter change to offset bad gearing. -1 wheel diameter (and shorter tire) will likely exacerbate bad gearing with your 6-speed.

You could easily put 255s on the 8.5" wheel...what are the other DS WRX people doing?

Just checked tirerack for other wheel options---yowza, those are expensive choices. :shock:

markmerrill · **Joined:** Fri Apr 30, 2010 3:21 pm **Posts:** 48

You see why I balk a bit? I think I'm at over 2k for shipping + wheels + tires + tpms + tpms tool for swapping the car between tpms sensors. :-(

Quite a bit more than I'd hoped to spend. And that's with an offset of 50 not 55 (the 55 offset wheels are ludicrously expensive).

The car came with 245s on it. 255s... and with 5mm further out from just the rim, will it fit? I'm finding it difficult to search for due to folks talking about the STI and many more interested in the look than in performance. I did find some folks saying that you tend to lose feel if you go too wide?

This looks possibly promising... just a bunch of money to "hope" about. Would probably need to join a forum and actually ask the question unless one of you fine folks has experience with this car/wheel combination.
http://www.willtheyfit.com/index.php?wi ... offset2=50

Chad Culbertson · **Posted:** Tue Mar 28, 2017 11:40 am

You think that's expensive? I was looking at $3k just for some TSWs and tires for the Camaro!

Steven Carter · **Posted:** Tue Mar 28, 2017 11:55 am

markmerrill wrote:

You see why I balk a bit? I think I'm at over 2k for shipping + wheels + tires + tpms + tpms tool for swapping the car between tpms sensors. :-(

Quite a bit more than I'd hoped to spend. And that's with an offset of 50 not 55 (the 55 offset wheels are ludicrously expensive).

The car came with 245s on it. 255s... and with 5mm further out from just the rim, will it fit? I'm finding it difficult to search for due to folks talking about the STI and many more interested in the look than in performance. I did find some folks saying that you tend to lose feel if you go too wide?

This looks possibly promising... just a bunch of money to "hope" about. Would probably need to join a forum and actually ask the question unless one of you fine folks has experience with this car/wheel combination.
http://www.willtheyfit.com/index.php?wi ... offset2=50

Yes, 255s will fit on an 8.5" wheel. BS S2000s do it all the time. As to whether there is a rubbing issue--no idea, so defer to others who may have tried that fitment on your car. I have heard some say they "lose feel" when they go with a wider tire, but they also end up going faster, so...you have to experiment to find out. In re TPMS--my GH WRX had an ECU that was TPMS-agnostic and didn't care if the light was lit or not. Has something changed where TPMS causes nanny-interference in the newer models? If not, just put a piece of tape over the annoying light and press on. It will likely be cheaper to just swap out tires in the offseason and stay with OE wheels than have two sets, even if you have to have the TPMS rebuilt on occasion.

As for wheels I failed to look at 50 offset options--whew! Those are more reasonable with Enkeis in the $220 range. I would join NASIOC and cruise their FS/FT forums for options. You could always join the local/regional FB Subaru community, but if it's like the S2000 ones the signal:noise ratio is pretty low-- so be patient.

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