[honorarysail]

Hey all, not super educated on wheel fitment but watched fitment industries video on the perfect fitment (

) and in the outro they stated that 18x9.5 38mm wrapped in 255/35s is the perfect fitment and the example footage looked sick. When i ordered through their site and selected the options “no rubbing” and “stock suspension”, these sizes fell within range. Upon doing some post purchase research (the wheels are sitting 10 feet from me), it looks like this is impossible to fit on stock suspension without modifying? I’m not sure why they’d suggest this sizing and now i’m just worried it’s not gonna work. Has anyone been misled by fitment industries/are they accurate?

 

[bradsm87]

Yep that's very aggressive fitment on the rear with sensible street camber IMO.

Do you plan on changing the suspension? If not, aggressive fitment just looks weird at stock ride height always. You're better off with some 18x8.5 +42-ish rear and +37-ish front with 225/40R18 with stock suspension and front camber bolts IMO.

 

[TRU-BOOST]

Big power plans? Thats enough tire for 500HP.

 

[Vtor]

Thumbnail looks like retarded levels of camber.

 

[EVASIVE TRUENO]

9.5 with a 255 wont work. 9 wide will. I'm running a 9 wide w/ a 255/35.

 

[bradsm87]

9.5 with a 255 wont work. 9 wide will. I'm running a 9 wide w/ a 255/35.

There are a lot more variables than that. The top of the tyre, where it scrubs the rear wheel arches, doesn't change much at all by going 0.5" narrower at the rim if the tyre size is the same. 255s with +38 offset with sensible street camber absolutely will scrub no matter what brand the tyre is.

 

[EVASIVE TRUENO]

There are a lot more variables than that. The top of the tyre, where it scrubs the rear wheel arches, doesn't change much at all by going 0.5" narrower at the rim if the tyre size is the same. 255s with +38 offset with sensible street camber absolutely will scrub no matter what brand the tyre is.

No need to explain this to me, im well aware. Im just letting the OP know that 9 wide with a 255 works fine and is perfectly functional, requires no cutting and no RLCA.

 

[bradsm87]

No need to explain this to me, im well aware. Im just letting the OP know that 9 wide with a 255 works fine and is perfectly functional, requires no cutting and no RLCA.

That depends on the wheel offset. Wheel offset is an essential variable.

 

[20mmrain]

I've almost been mislead by fitment industries staff. After telling on of their employees what I read looking for, in terms of fitment on my 23 GR86, they directed me to wheels that were 18x9.5 @+30 offset, with a 245 40R18 tire.
While a wheel like this can fit in the GR86, it would have only been after major modifications. (Including fender tucking)
Otherwise there would have been some major poke and rubbing.

(If you use their auto lookup on their website it's even worse)

I was looking for a flush fitment on only about 1 inch of drop. After doing my own research, I ended up with a 18x8 +35 offset with a 215 40r18 tire, and I couldn't be happier.

If you ask me, look at fitment industries gallery (which is pretty accurate) and do your own research. Don't rely on their advice for fitment.

Who knows maybe I just got a bad employee, but it didn't leave me with a good experience.

If you don't want to modify your suspension that much (if at all) you're looking at 18x8 +35 or 18x8.5 +40 with a 215 40r 18 or 225 40r 18 tire. Both will bring the wheels out about 20mm for flush fitment without wheel rub on the Gen 2 BRZ/GR86.

 

[Bergman]

With that size wheel, offset and tire size. You're definitely doing some cutting or some major suspension arms. That's an aggressive setup for coilovers even, I can't imagine stock suspension. I would see if you can get your money back from them and order a more suitable size for stock suspension, if that's where you want to stay at.

 

[Shiba Speed]

Big power plans? Thats enough tire for 500HP.

Is there a tire size (or total tire surface area) to HP rule of thumb?

 

[TRU-BOOST]

Meh, not really. Too many other factors like suspension, total weight, weight balance, sway bar setup, tire compound, etc to just put a number on it. But my experience with this platform is that a ton of people just slap giant ass tires on them for looks without having any idea the impact that makes on the total driving picture. It isnt as simple as "bigger is better" in many cases. To me a 255 on this car may make a great short\medium track tire, but a bad street tire.
My opinion.

 

[Bergman]

Meh, not really. Too many other factors like suspension, total weight, weight balance, sway bar setup, tire compound, etc to just put a number on it. But my experience with this platform is that a ton of people just slap giant ass tires on them for looks without having any idea the impact that makes on the total driving picture. It isnt as simple as "bigger is better" in many cases. To me a 255 on this car may make a great short\medium track tire, but a bad street tire.
My opinion.

Hi 🤚

 

[EVASIVE TRUENO]

Meh, not really. Too many other factors like suspension, total weight, weight balance, sway bar setup, tire compound, etc to just put a number on it. But my experience with this platform is that a ton of people just slap giant ass tires on them for looks without having any idea the impact that makes on the total driving picture. It isnt as simple as "bigger is better" in many cases. To me a 255 on this car may make a great short\medium track tire, but a bad street tire.
My opinion.

The differences are not as drastic as the numbers may appear in your head. A sub 1% diameter change is about as good as it gets when changing tire spec from OEM.
Pairing my 255/35 with a set of forged wheels as I've done is probably about as good as it gets for a do it all setup in my eyes. Everyone has their own opinion though.

At least on paper, in comparison to OEM spec there is effectively no real life noticeable speedometer error or power loss. However, a whole lot more confidence inspiring meat on the wheels. More popular and "conservative" setups like 235/40 for example has roughly a 2.5% diameter difference.

 

[honorarysail]

The differences are not as drastic as the numbers may appear in your head. A sub 1% diameter change is about as good as it gets when changing tire spec from OEM.
Pairing my 255/35 with a set of forged wheels as I've done is probably about as good as it gets for a do it all setup in my eyes. Everyone has their own opinion though.

At least on paper, in comparison to OEM spec there is effectively no real life noticeable speedometer error or power loss. However, a whole lot more confidence inspiring meat on the wheels. More popular and "conservative" setups like 235/40 for example has roughly a 2.5% diameter difference.

View attachment 23036

Thank you for this explanation, I was going to ask next how drastic of a difference it would be, I do plan to turbo it when smaller kits are released down the road and maybe track it once or twice, but yeah it is mostly for daily driving, which 255s add more straight line grip too right? Whereas performance in drifts would be slightly hindered per what i’m seeing?

 

[mhcoutts]

Just had 18x9.5 37mm offset with 255 35s today. I'm on RCE SS1 with no control arm mods. roughly -1.5 front and rear.

 

[TRU-BOOST]

The differences are not as drastic as the numbers may appear in your head. A sub 1% diameter change is about as good as it gets when changing tire spec from OEM.
Pairing my 255/35 with a set of forged wheels as I've done is probably about as good as it gets for a do it all setup in my eyes. Everyone has their own opinion though.

At least on paper, in comparison to OEM spec there is effectively no real life noticeable speedometer error or power loss. However, a whole lot more confidence inspiring meat on the wheels. More popular and "conservative" setups like 235/40 for example has roughly a 2.5% diameter difference.

View attachment 23036

Agree the diameter is spot on. I was talking more about the width. I see no reason to run 20% more tire on these cars on the street, unless its for looks only. Most of the time I feel my 215 PS4 tires are too much grip honestly. My only point was that I think people get carried away thinking they need way more tire than they really do. We are working with 230HP here. I get it for cosmetic builds.

 

[jdmchris]

Agree the diameter is spot on. I was talking more about the width. I see no reason to run 20% more tire on these cars on the street, unless its for looks only. Most of the time I feel my 215 PS4 tires are too much grip honestly. My only point was that I think people get carried away thinking they need way more tire than they really do. We are working with 230HP here. I get it for cosmetic builds.

I agree. If this is a street only car, the only reason to go that width would be for looks. Going from OE tire size to 255's and Aero caused like a 10mpg loss, on my track car.

 

[EVASIVE TRUENO]

I agree. If this is a street only car, the only reason to go that width would be for looks. Going from OE tire size to 255's and Aero caused like a 10mpg loss, on my track car.

I'm sorry, but 255's did not cause you a 10 MPG hit. Let's get real here. The diameter difference from OE to 255 as I've already posted is less than 1%. It's a 10 rotation per mile difference. Depending on the severity / aggressiveness of the aero you're running I could see a significant MPG drop happening from that.

 

[jdmchris]

I'm sorry, but 255's did not cause you a 10 MPG hit. Let's get real here. The diameter difference from OE to 255 as I've already posted is less than 1%. It's a 10 rotation per mile difference. Depending on the severity / aggressiveness of the aero you're running I could see a significant MPG drop happening from that.

They were RE-71R tires. Before the aero it was at least 7mpg. The Aero wasn't aggressive. It was a track car that was occasionally driven to work and events in. But the sticky wide tires absolutely killed my MPG.