Wheel width for 315mm squared?

[roguegeek]

Second gen Camaro with full Speedtech ExtReme subframe and rear torque arm. This thing is capable of doing 335 squared with no clearance issue, but I don’t see a reason to go beyond 315 on all four corners. At 18” wheels, what width should I be looking into?

[130fe]

315s and 11” wheels go well together.

[roguegeek]

315s and 11” wheels go well together.

And if for some reason I did want to push 335 in the rear at some point, would an 11” width cut it?

[Jonathonar89]

And if for some reason I did want to push 335 in the rear at some point, would an 11” width cut it?

For reference, the MINIMUM recommended width for BFG Rival is 11.5"...

BFGoodrich g-Force Rival S 1.5 | P335/30ZR18 (tirerack.com)

[carbuff]

I used 11" from and 11.5" rear. Both worked well with BFG Rival 1.5's at 315. I think a 12" width would be better for a 335, but I'm not sure how many manufacturers are still making that width.

[68Formula]

I'd do the 11.5".

[roguegeek]

For reference, the MINIMUM recommended width for BFG Rival is 11.5"...

BFGoodrich g-Force Rival S 1.5 | P335/30ZR18 (tirerack.com)

Ok. So the most likely 315 tires would be Falken Azenis RT660 315/30ZR18 or BFGoodrich g-Force Rival S P315/30ZR18/LL 91W. The Falkens have a range of 10.5-11.5" with the BFGs at 10.9-11.5". If I were to ever move up to a 335, it would be something like a Rival S P335/30ZR18/LL 95W which has a range of 11.5-12.5". It sounds like if I wanted to be flexible with the tire, I would want to go with a 11.5" width on the wheel. Correct? So if that was right, I would be pushing the upper limit of a 315 and lower limit of a 335. For all the people who know much more than I do, is that a concern?

[roguegeek]

I used 11" from and 11.5" rear. Both worked well with BFG Rival 1.5's at 315. I think a 12" width would be better for a 335, but I'm not sure how many manufacturers are still making that width.

How do you normally have your tires set up with the offset wheel widths? 315 squared?

I'd do the 11.5".

11.5 if sticking with 315 or 11.5 for 315 with the option of doing 335?

[dontlifttoshift]

I just mounted a bunch of 315s. Falkens look way better on a 12 than on an 11. Also, not much difference between the Falken 315 and BFG 335 on a 12.

Yokohama A052s always look stretched because they don't have a rim protector molded in but I can confirm that they mount easily on a 12.5" rim and have seen them on 13s.

I am pretty sure you can run 12" wheels square on that car with that suspension so I would.

[68Formula]

11.5 if sticking with 315 or 11.5 for 315 with the option of doing 335?

I was referring to the 315s with option to 335s. Originally I was thinking a 12" would be better, but interestingly Falken didn't recommend more than 11.5" on the 315. Based on dontlifttoshift's feedback a 12" setup would be more ideal even for 315s, and better especially if you went up to 335s later on. I prefer having the overall rim width (outside to outside) at least as wide as the overall tire width if possible. It'd be better if you really decide which size you want to go with first.

[Jonathonar89]

I would follow Donny’s experience here.

The advertised tread width for the BFG Rival 315 is 11.7”. I personally would strive to run a 315 on a 11.5-12” wheel mounting width to stay in line with the tread width. Doing so keeps the shoulders of the tire squared. A 335 on the same wheel would be “pulling over” the shoulders of the tire slightly.

[carbuff]

How do you normally have your tires set up with the offset wheel widths? 315 squared?

My front and rear offset were different, as were the widths. So while I had 315's at all 4 corners, I couldn't rotate anything without unmounting / remounting (if this is what you were asking).

I personally liked the fit of the 315 Rivals on the 11.5" width also.

Best suggestion I can make... Get one of the wheel fitment tools and the tire you plan to run and test very carefully to make sure you are getting everything correct in terms of fitment if you are going to squeeze a 335 under the car. The shape of the Camaro wheel openings make it a little tighter than the Firebird (which I had). And if/when in doubt on offset, I'd go a little conservative and use more offset (I think that's how it's stated) as you can always use a small spacer to push the wheel out if needed (as in a 1/4" size or so, don't go too conservative).

[roguegeek]

I just mounted a bunch of 315s. Falkens look way better on a 12 than on an 11. Also, not much difference between the Falken 315 and BFG 335 on a 12.

Yokohama A052s always look stretched because they don't have a rim protector molded in but I can confirm that they mount easily on a 12.5" rim and have seen them on 13s.

I am pretty sure you can run 12" wheels square on that car with that suspension so I would.

Thanks for the feedback. I'm less concerned with how they look on the car and am more concerned I'm running an optimal setup. The car will accept 12" all around, but in talking with the Speedtech guys, I'm finding everyone is moving away from 335 and sticking with 315, which is what I'm very likely going to do. I was just asking about 335 flexibility, but it's really not that important to me here. At 315 squared, you'd still recommend 12? Even though Falken doesn't recommend over 11.5?

I was referring to the 315s with option to 335s. Originally I was thinking a 12" would be better, but interestingly Falken didn't recommend more than 11.5" on the 315. Based on dontlifttoshift's feedback a 12" setup would be more ideal even for 315s, and better especially if you went up to 335s later on. I prefer having the overall rim width (outside to outside) at least as wide as the overall tire width if possible. It'd be better if you really decide which size you want to go with first.

I'm set on 315. I was just wondering about 335 compatibility, but it was just to gather info. 335 shouldn't be taken into consideration for this particular decision. Thoughts?

I would follow Donny’s experience here.

The advertised tread width for the BFG Rival 315 is 11.7”. I personally would strive to run a 315 on a 11.5-12” wheel mounting width to stay in line with the tread width. Doing so keeps the shoulders of the tire squared. A 335 on the same wheel would be “pulling over” the shoulders of the tire slightly.

Yup. Let's throw the 335 conversation away at this point then. I'm going to be running 315 squared.

My front and rear offset were different, as were the widths. So while I had 315's at all 4 corners, I couldn't rotate anything without unmounting / remounting (if this is what you were asking).

I personally liked the fit of the 315 Rivals on the 11.5" width also.

Best suggestion I can make... Get one of the wheel fitment tools and the tire you plan to run and test very carefully to make sure you are getting everything correct in terms of fitment if you are going to squeeze a 335 under the car. The shape of the Camaro wheel openings make it a little tighter than the Firebird (which I had). And if/when in doubt on offset, I'd go a little conservative and use more offset (I think that's how it's stated) as you can always use a small spacer to push the wheel out if needed (as in a 1/4" size or so, don't go too conservative).

Yes, I was asking for the purpose of rotation. Thanks for the details here. For this particular wheel purchase, I'm only considering 315. At this point, I'm leaning towards 11.5, but I'm all ears to hear more experience on this.

[Jonathonar89]

I don’t think you will miss much in either direction. 11.5” obviously gives you the all-around option here.

[roguegeek]

I don’t think you will miss much in either direction. 11.5” obviously gives you the all-around option here.

Yeah, that's what I'm thinking too.

[dontlifttoshift]

Yes, I would run 12" wheels with 315s. People are moving away from the 335 because it only exists in 18" in the Rival and it's not as fast as the A052 or the RT660.

Stretching the tire some (not talking about the hellaflush stance guys) supports the sidewall better which in turn allows you to dump some air pressure. Less air, more grip, more grip, more fast. Turn in is crisper and the rear of the car will break away cleaner as it is less likely to load up the sidewall and snap to over steer.

In order to run this setup square, you start with the front. So that's 18x12 and I believe the backspace number is 8ish inches. Confirm that number with SpeedTech!! Then you build your rearend to the width that properly locates the wheels in the wheel house. In the theoretical case of 8" backspace on a 18x12, your rear end width would be approximately 65" from wheel mount surface to wheel mount surface.

[roguegeek]

Yes, I would run 12" wheels with 315s. People are moving away from the 335 because it only exists in 18" in the Rival and it's not as fast as the A052 or the RT660.

Stretching the tire some (not talking about the hellaflush stance guys) supports the sidewall better which in turn allows you to dump some air pressure. Less air, more grip, more grip, more fast. Turn in is crisper and the rear of the car will break away cleaner as it is less likely to load up the sidewall and snap to over steer.

In order to run this setup square, you start with the front. So that's 18x12 and I believe the backspace number is 8ish inches. Confirm that number with SpeedTech!! Then you build your rearend to the width that properly locates the wheels in the wheel house. In the theoretical case of 8" backspace on a 18x12, your rear end width would be approximately 65" from wheel mount surface to wheel mount surface.

Ok. A lot of really good info here. I'll give Speedtech a call and see what they say in terms of backspace. My Dutchman rear-end is 56".

[roguegeek]

I'd like to expand the scope of my questions here. Let's say I go with 18x11.5, that will allow me to run all of the available 315/30ZR18 tires out there. What I haven't thought about is tires for when I'm daily driving. Yes, I could get a set of wheels that will better accept tires for the street, but what kind of smaller sizes could I fit on the 18x11.5? Could I fit a 295/30R18 like ones found in the Falken Azenis KF510 or comparable tire? Sizes where I can get higher UTQG ratings and are more mannered for daily driving. Would an 18x11.5 be capable of running something like that?

[dontlifttoshift]

Do you have the ability to mount and balance your own tires? The time and money spent swapping tires all the time gets old......hell, it gets old when you have your own equipment.

I just mounted a 295/30 A052 on an 11.5. It fit fine.

I will readily admit that I don't understand the willingness to stretch the DD tires past the recommended specs for no advantage while at the same time unwilling to stretch the race tires.

[68Formula]

295/30s are really short on a 2nd gen. I'd look at the 295/35s.