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As our 18" flow-formed wheels have become a popular option for Supra owners looking to decrease wheel diameter, we've been collecting feedback about various fitment options including aggressive tire fitments in taller sizes that have caused rubbing issues with the factory spring perch on the front struts. With new details about both our test fitment and other tire sizes and models from customers, I wanted to create this thread to give Supra owners an idea of what various tire fitments look like on the A90 platform with our 18x10 ET30 wheels and bring up additional points to consider when selecting tires in general.
18x10 ET30 SM-10 with 285/35-18 Pirelli P Zero tires front & rear. Front 5mm spacer required for clearance. Photo/Car credit: @nibble
The front OE spring perch within the A90 Supra wheel wells is the limiting factor when it comes to tire clearance with this chassis. The perch captures the lower end of the spring and consists of a metal plate and rubber isolator pad. The portion of the pad that comes into contact with a wide wheel and tire package can be trimmed or allowed to "self-clearance" to gain a few more mm of clearance on the inner edge but the plate would have to be ground down slightly to improve any clearance if the steel perch is contacting the tire. Aggressive tire models that run wide in taller 18" fitments like 275/40-18 can contact not only the rubber isolator on the spring perch but also the metal perch beneath. Here are some images of the strut assembly and perch itself with the potential areas that might experience rubbing highlighted:
This limited clearance with the OE suspension affects the models and sizes of front tires you can run on these wheels as a direct fit. This will also inherently limit your rear tire size if your goal is to run these wheels and tires as a rotatable fitment. There are several options to improve inner clearance that do not involve the tires themselves:
275/35-18 Maxxis Victra RC-1s on our 18x10.5 et38 EC-7Rs
Lastly, with the true width of some of these aggressive 275/40-18 tires, a wider wheel is really the more ideal choice for overall sidewall support and tire performance. R compound tires with thick sidewalls benefit from the additional sidewall support a wider wheel provides and 275/40-18 is an extremely common size to see on our 18x10.5 ET38 square EC-7Rs:
18x10.5 et38 EC-7Rs with 275/40-18 Yokohama A052s front & rear. 12mm front spacers required. Owner's IG: @tim.onetime
Fitment Feedback:Our fitment guide has been updated with this tire feedback as we've received it, but we are always ready for more. If you are running these wheels and have additional notes or questions, please let us know in either the thread below or via DM/email to [email protected]. Our fitment guide with notes about tires and additional fitments can be found here.
A huge thanks goes out to the forum members who have worked with us and provided photos and feedback about these wheels already. I've worked directly with many of you and appreciate the photos and feedback. I believe I've attributed photo credit to everyone correctly with these images, but please reach out with any corrections if that isn't the case.
-Tom
Background:
Our 18x10 ET30 SM-10 Supra wheels were made to be run as a square setup as well as serve as the front wheel for our staggered fitment with 18x11 ET40s in the rear. If these wheels had been designed purely as a front wheel the ideal offset would be lower to give more clearance around the front strut assembly. We knew a rotatable 18x10 fitment was in demand as well so these wheels needed to be a direct fit in the rear of the car which required a higher offset. As you can see in these images, an 18x10 ET30 sits just within the rear wheel well of the car:
18x10 ET30 SM-10 with 285/35-18 Pirelli P Zero tires front & rear. Front 5mm spacer required for clearance. Photo/Car credit: @nibble
The front OE spring perch within the A90 Supra wheel wells is the limiting factor when it comes to tire clearance with this chassis. The perch captures the lower end of the spring and consists of a metal plate and rubber isolator pad. The portion of the pad that comes into contact with a wide wheel and tire package can be trimmed or allowed to "self-clearance" to gain a few more mm of clearance on the inner edge but the plate would have to be ground down slightly to improve any clearance if the steel perch is contacting the tire. Aggressive tire models that run wide in taller 18" fitments like 275/40-18 can contact not only the rubber isolator on the spring perch but also the metal perch beneath. Here are some images of the strut assembly and perch itself with the potential areas that might experience rubbing highlighted:
- Upgrading to aftermarket suspension with better inner clearance
- Upgrading to a coilover with a smaller overall diameter than the OE spring and perch configuration or a reduced stack height that moves the springs up and away from the tire will improve inner clearance. Motorsport-oriented coilovers like MCS or JRZ will tend to have a more compact design and a slimmer overall silhouette that will maximize inner clearance on most applications.
- This is obviously the most expensive option and should be done for improved suspension performance with better inner clearances being a secondary benefit of the upgrade.
- Certain HAS (height adjustable spring) kits we've tested have increased inner clearance. We have a customer running an HKS HAS kit with 19x11 ET40 wheels up front without spacers. Not all HAS kits will increase inner clearance though so purchase with care.
- Running a front spacer
- This is the simplest option for customers looking to run taller tire configurations in aggressive models of tire that run wide.
- Spacers move the wheel and tire package away from the strut and spring perch. 5mm spacers have typically been enough to resolve any rubbing issues with the tires we've seen and leave enough of the OE hubcentric ring exposed to keep the wheels hubcentric and prevent vibrations.
- Be sure to run extended-length bolts or a stud conversion kit with any wheel spacers.
- The spacer may move the wheel and tire out enough to create contact between the upper portion of the tire on the outside edge and the fender during heavy suspension compression. This can be dialed out with additional negative camber.
- Trimming of the rubber isolator pad and grinding of the OE steel spring perch
- This is the cheapest option but it is also the most invasive for obvious reasons.
- There is enough rubber material on the outer edge of the strut to remove some of it and grind away a portion of the perch to improve clearances, but this should be done with care.
Tire Data:
While the above alternatives are options, we recognize that the majority of our customers running these wheels are looking for a bolt-on solution with their wheel and tire setup. With that in mind, this section will cover the fitments that we've seen thus far that have either been a direct fit with zero modifications or those that have had rubbing issues and what was done to solve those issues. A brief summary for this section: If you are looking for an easy fitment, tires with shorter sidewalls are the go-to option including most 275/35-18 and 265/35-18 tires. Tire data and measurements are taken from Tire Rack or the manufacturer's website when available.
265/35-18
Tire model: Hankook RS-4 (200 TW)
Section Width: 11"
Tread Width: Unlisted
Overall diameter: 25.1"
APEX Notes: Direct fit.
RS-4s are known to run wide across their range so most other 265/35-18 tires will have much better clearance than the RS-4 pictured below. Photo credit: Joe McGuigan
---------------------------------
265/40-18
Tire model: Continental Extreme Contact Sport (340 TW)
Section Width: 11.2"
Tread width: 9.4"
Overall diameter: 26.3"
APEX Notes: Direct fit.
This is another tire that runs wide despite the listed size. This tire clears the OE perch, but is quite close to the rubber isolator because of the taller overall tire package. This is a great option for owners looking to run a taller tire without modifications. Photo credit @Last Lemming
Front wheels pictured are 18x10 ET30, rears are 18x11 ET40. No spacers were used in any of these photos.
---------------------------------
275/35-18
Tire model: Falken Azenis RT615k+ (200TW)
Section Width: 10.8"
Tread Width: 9.7"
Overall Diameter: 25.6"
APEX Notes: Direct fit.
These Falkens run narrower than the Hankook RS-4s one listed size smaller and have great clearance thanks to their shorter sidewall. Photo/Car Credit: @Evolution
Front wheels pictured are 18x10 ET30, rears are 18x11 ET40. No spacers were used in any of these photos.
---------------------------------
275/35-18
Tire model: Continental Extreme Force (200TW)
Section Width: 11.1"
Tread Width: 9.5"
Overall Diameter: 25.5"
APEX Notes: Direct fit??*
Customer is running 5mm spacers to avoid rubbing via tire deflection, but setup appears to clear without spacers. Photo Credit: @kyippee
left photo: No spacers. Right photo: 5mm spacers.
---------------------------------
275/40-18
Tire model: Yokohama Advan A052s (200TW)
Section Width: 11"
Tread Width: 9.8"
Overall Diameter: 26.7"
APEX Notes: Mods required.
This tire was used for our initial testfit and photoshoots. At the time, we thought they were a direct fit as the cars tested drove fine without signs of rubbing or witness marks on the tire sidewalls, but after a second testfit we noted that the tire touches the rubber isolator and would not be a direct fit. Corrections will be made to our previous posts and we have updated our fitment guide with this new information. 5mm spacers should allow these tires to clear, but they will not be a direct fit. These tires do run wider than many other tire models in this size. Less aggressive tires with narrower section widths may clear without a spacer in this size.
Front wheels pictured are 18x10 ET30, rears are 18x11 ET40. No spacers were used in any of these photos.
---------------------------------
275/40-18
Tire model: Goodyear Eagle F1 Supercar 3 (220TW)
Section Width: Unlisted
Tread Width: 9.4"
Overall Diameter: 26.7"
APEX Notes: Mods required.
These tires rubbed the rubber isolator and metal portion of the perch. Based on our test fitment of the A052s in the same size, we suspect that their section width is wider than 11" based on their fitment compared to the Yokohamas despite a narrower listed treadwidth on Goodyear's site. Neither Goodyear's site nor Tire Rack list a section width for these tires, but they are quite wide. Photo Credit: @gcmak, Joe McGuigan.
Without Spacers:
With a 5mm spacer:
---------------------------------
285/35-18
Tire model: Pirelli P Zero (220 TW)
Section Width: 11.6"
Tread Width: 10"
Overall Diameter: 26
APEX Notes: Mods required.
These tires are the widest size we recommend for the 18x10 ET30 wheels but even with the shorter sidewall, they are not a direct fit. 5mm spacers will be required with most tires in this size with wider tire models requiring thicker spacers. Additional negative camber can help increase outer tire/fender clearance when spacers are used but alignment adjustments aren't always necessary. Photo/Car Credit: @nibble
Without Spacers:
With 5mm Front Spacers:
Isolator wear caused by fitment prior to the addition of spacers.
Alignment notes for this setup:
---------------------------------
Additional Considerations:
True tire dimensions are not always reflected by the listed size the tires are sold under. This is especially prevalent on the higher-performance end of tire sizes as manufacturers seek to bring a tire to market that outperforms the competition. This leads to tires that run wide both on the tread and section width which can result in unwanted rubbing. We often hear from customers who want to run taller 18" tires to match the OE rolling diameter of the stock 19" wheels and tires. While ideally we would like to have a perfect match, the realities of the fitment constraints on this chassis mean that a 265/35-18 or 275/35-18 tire will be a much easier fit overall if you are running the stock suspension. We have customers running 265/35-18 and 275/35-18 square setups with no traction control or stability control issues on the track or street and overall tire availability is excellent in these sizes giving you access to a wider range of performance tire options. The taller tires can be used, but modifications are often required and should be kept in mind when purchasing tires.Tire model: Hankook RS-4 (200 TW)
Section Width: 11"
Tread Width: Unlisted
Overall diameter: 25.1"
APEX Notes: Direct fit.
RS-4s are known to run wide across their range so most other 265/35-18 tires will have much better clearance than the RS-4 pictured below. Photo credit: Joe McGuigan
---------------------------------
265/40-18
Tire model: Continental Extreme Contact Sport (340 TW)
Section Width: 11.2"
Tread width: 9.4"
Overall diameter: 26.3"
APEX Notes: Direct fit.
This is another tire that runs wide despite the listed size. This tire clears the OE perch, but is quite close to the rubber isolator because of the taller overall tire package. This is a great option for owners looking to run a taller tire without modifications. Photo credit @Last Lemming
Front wheels pictured are 18x10 ET30, rears are 18x11 ET40. No spacers were used in any of these photos.
---------------------------------
275/35-18
Tire model: Falken Azenis RT615k+ (200TW)
Section Width: 10.8"
Tread Width: 9.7"
Overall Diameter: 25.6"
APEX Notes: Direct fit.
These Falkens run narrower than the Hankook RS-4s one listed size smaller and have great clearance thanks to their shorter sidewall. Photo/Car Credit: @Evolution
Front wheels pictured are 18x10 ET30, rears are 18x11 ET40. No spacers were used in any of these photos.
---------------------------------
275/35-18
Tire model: Continental Extreme Force (200TW)
Section Width: 11.1"
Tread Width: 9.5"
Overall Diameter: 25.5"
APEX Notes: Direct fit??*
Customer is running 5mm spacers to avoid rubbing via tire deflection, but setup appears to clear without spacers. Photo Credit: @kyippee
left photo: No spacers. Right photo: 5mm spacers.
---------------------------------
275/40-18
Tire model: Yokohama Advan A052s (200TW)
Section Width: 11"
Tread Width: 9.8"
Overall Diameter: 26.7"
APEX Notes: Mods required.
This tire was used for our initial testfit and photoshoots. At the time, we thought they were a direct fit as the cars tested drove fine without signs of rubbing or witness marks on the tire sidewalls, but after a second testfit we noted that the tire touches the rubber isolator and would not be a direct fit. Corrections will be made to our previous posts and we have updated our fitment guide with this new information. 5mm spacers should allow these tires to clear, but they will not be a direct fit. These tires do run wider than many other tire models in this size. Less aggressive tires with narrower section widths may clear without a spacer in this size.
Front wheels pictured are 18x10 ET30, rears are 18x11 ET40. No spacers were used in any of these photos.
---------------------------------
275/40-18
Tire model: Goodyear Eagle F1 Supercar 3 (220TW)
Section Width: Unlisted
Tread Width: 9.4"
Overall Diameter: 26.7"
APEX Notes: Mods required.
These tires rubbed the rubber isolator and metal portion of the perch. Based on our test fitment of the A052s in the same size, we suspect that their section width is wider than 11" based on their fitment compared to the Yokohamas despite a narrower listed treadwidth on Goodyear's site. Neither Goodyear's site nor Tire Rack list a section width for these tires, but they are quite wide. Photo Credit: @gcmak, Joe McGuigan.
Without Spacers:
With a 5mm spacer:
---------------------------------
285/35-18
Tire model: Pirelli P Zero (220 TW)
Section Width: 11.6"
Tread Width: 10"
Overall Diameter: 26
APEX Notes: Mods required.
These tires are the widest size we recommend for the 18x10 ET30 wheels but even with the shorter sidewall, they are not a direct fit. 5mm spacers will be required with most tires in this size with wider tire models requiring thicker spacers. Additional negative camber can help increase outer tire/fender clearance when spacers are used but alignment adjustments aren't always necessary. Photo/Car Credit: @nibble
Without Spacers:
With 5mm Front Spacers:
Isolator wear caused by fitment prior to the addition of spacers.
Alignment notes for this setup:
---------------------------------
Additional Considerations:
275/35-18 Maxxis Victra RC-1s on our 18x10.5 et38 EC-7Rs
18x10.5 et38 EC-7Rs with 275/40-18 Yokohama A052s front & rear. 12mm front spacers required. Owner's IG: @tim.onetime
Fitment Feedback:
A huge thanks goes out to the forum members who have worked with us and provided photos and feedback about these wheels already. I've worked directly with many of you and appreciate the photos and feedback. I believe I've attributed photo credit to everyone correctly with these images, but please reach out with any corrections if that isn't the case.
-Tom
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