Originally Posted by whazzzzuup
It seems that every other question asked on this sub-forum is about wheel/tire fitment. If you guys have any questions, just post them in this thread. There are a lot of knowledgeable members that can answer these types of questions. That should help a lot with the clutter.
There is a thread that should/might be a sticky covering the subject:
Wheel Fitment Guide 2GS/IS-01-05/SC430
Wheels and Tires Fitment Guide
Creation Date: 3/2/2004
Modify Date: 10/26/2005 (SC430 information)
Originally Posted by raceforgt
I suppose I'll be the first to post something here. I've asked about this in another forum and was rudely told to search and not ask repeated questions about something that's been discussed elsewhere. I searched and found nothing to answer my exact questions.............
I don't think people were trying to be rude, it's just frustration from additional post going up on subjects that have been covered before. I'll post the GS section of the fitment guide (which needs to be updated):
GS wheels fitment
The stock GS 17" wheels, as far as I know, are 17x8 with 235/45/17. I have owned two sets of aftermarket wheels for the car, 19" VolkRacing AV3 19x8.5 +38 front and 19x9.5 +38 rear, and now I have the 20" HRE 540R 20x8.5 +32 front and 20x10 +43 rear. I would classify my 19" setup as a conservative setup as it doesn't flush totally with the fender but have zero rubbing issue, whereas with the HRE, the setup is very aggressive and is flush perfect with the fender, but has slightly rubbing which was fixed relatively easy.
The following are the wheel sizes that I would suggest for the GS (if you don't want to have a staggered setup, just put whatever for the front in the back). When I say the setup is conservative, it means you don't have to do any fender modification. When I say aggressive, that means you probably have to do the rolling or shaving. And in the case of professional, then some major suspension changes would have to be made in order to fit the wheel, and should be left to professionals hence I won't go over how here.
18x8 +32 18x9 +32 conservative
18x8.5 +38 18x9.5 +38 conservative
18x8.5 +38 18x10 +44 conservative
18x8.5 +32 18x10 +42 aggressive
18x9 +38 18x10 +42 aggressive
18x9 +35 18x10 +35 professional
19x8 +32 19x9 +32 conservative
19x8.5 +38 19x9.5 +38 conservative
19x8.5 +38 19x10 +44 conservative
19x8.5 +32 19x10 +42 aggressive
19x9 +38 19x10 +42 aggressive
19x9 +35 19x10 +35 professional
20x8.5 +38 20x9.5 +38 conservative
20x8.5 +38 20x10 +44 conservative
20x8.5 +32 20x10 +42 aggressive
20x9 +38 20x10 +42 aggressive
20x9 +35 20x10 +35 professional
** on 20" wheels for the GS, keep in mind that the wheels are out of spec so the overall diameter is off by about 6%. Your speedometer would be off, meaning that when the speedometer says 80mph, you are actually going at around 85mph already. Plus, because of the 1" larger diameter overall compared to 18" or 19" (with tires), you have to be careful with your lowering. From my experience, if you lower your car to 2 fingers, provided that you have the correct offset, you shouldn't rub (or very slightly) the top of the wheel well. If you go 1½ finger gap or less, when going over uneven road or dips, you will most likely rub the top part of the wheel well. Over time you will see part of the rubber wheel well flap got rubbed away. Moreover, with 20", you will rub when you put your steering wheel at full lock (either left or right) and mostly when backing up. This is due to the bigger diameter and when you turn, you rub the front and back of the wheel well (this is one reason why 20" are the biggest rims you can put on the GS with reasonable widths).
When it comes to tires for the GS, the following setup are preferred:
Wheel Size Tires Within Spec?
18x8 235/40/18 245/40/18 yes
18x8.5 245/40/18 yes
18x9 245/40/18 255/40/18 yes
18x9.5 275/35/18 yes
18x10 275/35/18 285/35/18 yes
19x8 235/35/19 245/35/19 yes
19x8.5 245/35/19 yes
19x9 245/35/19 255/35/19 yes
19x9.5 275/35/19 yes
19x810 275/30/19 285/30/19 yes
19x8 235/40/19 245/40/19 no (fat setup)
19x8.5 245/40/19 no (fat setup)
19x9 245/40/19 255/40/19 no (fat setup)
19x9.5 275/35/19 no (fat setup)
19x10 275/35/19 285/35/19 no (fat setup)
20x8.5 245/35/20 no
20x9 245/35/20 255/35/20 no
20x9.5 275/30/20 no
20x10 275/30/20 285/30/20 no
Keep in mind different brands of tires, even with the same profile, will be different too. So for very marginal setup (read: aggressive), the tires might provide the 1 or 2mm that makes all the difference. Tires like the Bridgestone SO3 and Dunlop P9000 are very rounded and "meaty". The rounded corners will help to avoid rubbing. On the other hand, from my experience, Nitto, Pirelli, Yokohama, etc... tires are very "square" so they might enhance the rubbing factor.