NASA Tire Section Width - User Contributed Database

[pastoli]

I tested a 245/40/17 Hoosier A7 on a 9.5" wheel. It would not pass the 266mm template. The width rules were based off these tires on this size wheel working when they were getting data to create this width rule. Where is the accounting of manufacturing error? This seems ridiculous. I am now on a 225 to be compliant. Thanks!

[Greg G.]

I tested a 245/40/17 Hoosier A7 on a 9.5" wheel. It would not pass the 266mm template. The width rules were based off these tires on this size wheel working when they were getting data to create this width rule. Where is the accounting of manufacturing error? This seems ridiculous. I am now on a 225 to be compliant. Thanks!

I don't know where you got the idea that the rules were based off these tires on a 9.5" wheel, because the rules were based on R7's on a 9" wheel. We never tested these tires on a 9.5" wheel for the rules revision process. I personally tested them for my own car, and they did not fit. I'm not sure why some of the guys on here said they do fit. I also posted that there was some variability in the manufacturer's production of these tires, and they have assured us that they will stay within specifications going forward.

[Clavette]

I purchased both a 245/40/18 and 245/35/18 Hoosier R7 and neither of them would clear the 266 template dismounted. Not sure how someone got this to work on a rim with pressure???

 

245/40/18 's as you mention do not pass unmounted, but they do pass on 9.5" Arc-8 rims. I have some pictures posted on NASA MA Time Trial Facebook site. Why do they get skinnier on the rim - I do not know...but they do.

[NorcalTT]

I tested a 245/40/17 Hoosier A7 on a 9.5" wheel. It would not pass the 266mm template. The width rules were based off these tires on this size wheel working when they were getting data to create this width rule. Where is the accounting of manufacturing error? This seems ridiculous. I am now on a 225 to be compliant. Thanks!

I don't know where you got the idea that the rules were based off these tires on a 9.5" wheel, because the rules were based on R7's on a 9" wheel. We never tested these tires on a 9.5" wheel for the rules revision process. I personally tested them for my own car, and they did not fit. I'm not sure why some of the guys on here said they do fit. I also posted that there was some variability in the manufacturer's production of these tires, and they have assured us that they will stay within specifications going forward.

 

Can there not be some 'allowance' for lack of a better term for this manufacturing or whatever variability? Do people really think that 1-2mm difference in width as measured 30mm from the actual tread width is going to make any material difference in performance? 1-2mm is about the width of a pencil tip and for that we are going to make a bunch of folks buy new wheels? Anyone who thinks they were not winning because someone was running a 9.5 inch rim vs. a 9 inch will continue losing. We need to rethink rules like this before Super Touring gets renamed Super Tedious.

[kfennell]

275/35-15 fit on 15x9 Adventi S2 and Konig Dial in.

 

Wondering if anyone knows if they fit on a 15x10 or not? It was only a few MM to spare, so very close. They do not fit the template unmounted, so I am thinking they probably dont fit on a 10.

[rob_h]

On 2/6/2018 at 9:02 PM, Greg G. said:

I tested the 9" Arc-8 with the 245/40 x17 R7 with a date code of 2317, and it fit the 266mm tool by less than 1mm at 35 psi.

I'm a little concerned that there may be a significant variance between tires of different date codes of that specific model (although the later codes seem to be okay). So,

I suggest checking your specific tire. If it measures 275mm off the wheel, it is unlikely to pinch down to 266 by using a 9" wheel. If it is 270-271mm off the wheel, I would

think it would fit.

Hi,  Did this variation in date code ever prove to be a factor?  Any feedback on other rims?

 

[HLF]

Anyone know if the 255-35R18 R7 comes in under 266 on a 9" wheel? 

 

[DavidSinger]

On 4/23/2018 at 9:57 PM, Clavette said:

 

245/40/18 's as you mention do not pass unmounted, but they do pass on 9.5" Arc-8 rims. I have some pictures posted on NASA MA Time Trial Facebook site. Why do they get skinnier on the rim - I do not know...but they do.

Mounted and aired up they expand  -  UP -  through the tread area, pulling the sidewalls in a bit (and pushing the footprint into a convex curve if you inflate too much air)

The reason is the sidewalls are less pliant than the footprint.

[dennistucker]

Hi. With the recent addition of the Toyo RR to the 100 treadwear category for ST4, I am curious if anyone can confirm that a 255/40/17 RR on a 9-inch ARC-8 rim will fit the 266mm template?

[Rapidroy10]

Hello everyone,

I asked this question in the ST/SU area regarding tire fitment but have not got any response there yet. I am considering the same tire for my ST5 Mustang. Here is my post from last Thursday:

Happy New Year racers,

I hope plans for 2020 are starting strong.

I just wanted to revisit this thread for a moment. I have done a bit of searching regarding tire clearances, but couldn't find the combo I am considering listed anywhere.

Has anyone measured the Toyo Proxes RR in 255/40-17 on a 17x9 wheel?

My current combination is 17x9 BBS classic multi spoke wheels with Zestino 240/610-17 slicks (on my ST5 Mustang) that have an honest 1/2 inch of clearance in the 266 template. I feel the Toyos will be okay - my current tires are 10 inches overall width mounted and the Toyos are listed at 10.4 wide. I feel this will help make up what I'm giving up.

As always, I appreciate any and all thoughts.

Cheers

RR

[Magus2727]

On ‎1‎/‎7‎/‎2020 at 7:48 AM, Rapidroy10 said:

Hello everyone,

I asked this question in the ST/SU area regarding tire fitment but have not got any response there yet. I am considering the same tire for my ST5 Mustang. Here is my post from last Thursday:

Happy New Year racers,

I hope plans for 2020 are starting strong.

I just wanted to revisit this thread for a moment. I have done a bit of searching regarding tire clearances, but couldn't find the combo I am considering listed anywhere.

Has anyone measured the Toyo Proxes RR in 255/40-17 on a 17x9 wheel?

My current combination is 17x9 BBS classic multi spoke wheels with Zestino 240/610-17 slicks (on my ST5 Mustang) that have an honest 1/2 inch of clearance in the 266 template. I feel the Toyos will be okay - my current tires are 10 inches overall width mounted and the Toyos are listed at 10.4 wide. I feel this will help make up what I'm giving up.

As always, I appreciate any and all thoughts.

Cheers

RR

X2 on this request with Toyo RR now being given the +0.6 modification factor (reference 2020 V3.1 rules 6.3.2), I am guessing more people will be running this. 

 

Any update to the table in the drop box file?

 

the 205 on a 8" wheel appears to be 210mm at 30mm (per the box document) so that would lead me to belive that a 245/40 on a 9" wheel may be around 250-255 so would fit a 257mm template.   

[Brian Sasser]

Has anyone tried a Toyo RR 275/35r18 on an 18x11 rim? I'm particularly interested in the apex ec-7 but any data is helpful.

I need to find a TT4 wheel setup that fits within the 282mm template.

[NammyBoy]

On 1/25/2018 at 4:22 AM, Greg G. said:

Our testing of the 275/17 and 18 Hoosier on a 10" wheel had no problem fitting the 282mm tool.

Since 245/40R17 is wider than 266 mm, I’m thinking of trying the 275/35R17 next, since you say it is narrower than 282 mm. What wheel exactly was this tire tested on? Thank you!

[HLF]

On 2/6/2020 at 6:32 PM, Brian Sasser said:

Has anyone tried a Toyo RR 275/35r18 on an 18x11 rim? I'm particularly interested in the apex ec-7 but any data is helpful.

I need to find a TT4 wheel setup that fits within the 282mm template.

I will be trying 275 RR on 18x10 this week.

[HLF]

On 2/6/2020 at 6:32 PM, Brian Sasser said:

Has anyone tried a Toyo RR 275/35r18 on an 18x11 rim? I'm particularly interested in the apex ec-7 but any data is helpful.

I need to find a TT4 wheel setup that fits within the 282mm template.

The 275/35 R18 Toyo RR on the Apex EC7 18x10 fits with just under 1cm to spare. 

I think the 18x11 might stretch the tire out too much.

I did ask the guys at TrackDayTire.com to test the 282 tool on an unmounted 285. I hope they get back to me today. If it clears without being mounted I'm gonna try it on my 10" wide wheel. 

 

 

[Partee Racing]

On 5/18/2020 at 12:42 PM, HLF said:

The 275/35 R18 Toyo RR on the Apex EC7 18x10 fits with just under 1cm to spare. 

I think the 18x11 might stretch the tire out too much.

I did ask the guys at TrackDayTire.com to test the 282 tool on an unmounted 285. I hope they get back to me today. If it clears without being mounted I'm gonna try it on my 10" wide wheel. 

 

 

Did you get an answer?

 

--Peter

[HLF]

On 8/21/2020 at 6:06 PM, Partee Racing said:

Did you get an answer?

 

--Peter

Track Day Tire says its not a fit. Sorry for the slow reply. 

[Dunzcon]

The Goodyear Eagle RS Slick 275/35/18 on a 9.5 inch wheel, fits and Falls off of the 282MM gauge. Its close but it passes. I have had it verified as well. 

tire.jfif

[MFMotorsports]

Has anyone tested the 255/35/18 toyo rr on a 18x10 wheel to see if they fit the 266mm rule?

[gogunbaba]

On 4/6/2018 at 12:49 PM, davidfarmer said:

I purchased both a 245/40/18 and 245/35/18 Hoosier R7 and neither of them would clear the 266 template dismounted. Not sure how someone got this to work on a rim with pressure???

Hi David, I confirm that 245/40/18 on 9.5" ARC-8 rim clears the NASA 266 template easily (5 mm to spare). I passed the tech 3 times at the nationals this year. 255/35/18 on the same rim will not clear.

[94tegls@MSC]

Currently running the numbers and planning for next years rule change and was wondering if anyone had experience with a 275/35R19 fitting the 282mm template?  I have a current set of 19x10.5" wheels but I doubt they'll fit the 282mm template, so was thinking of getting a set of Apex 19x9.5" or 19x10" wheels.  Probably planning on Nankang AR1's/Toyo R888R or a similar 100 treadwear/200 treadwear tire that ends up in the 1.6 bump for next year.  

[slyez]

As a datapoint for Toy RR 245/40/15, on 8" wheel, they measure around 245-247mm.  Looking to try them on a 9" wheel in a week or so.  on 8" wheel they are way less than the 257 template.

[hispanicpanic]

Now that hoosier has supposedly tightened up their manufacturing tolerances on measured width, can anyone confirm if the 245/40/15 hoosier R7 can fit on a 15x10? Or is 15x9 still the ticket for that tire?

[Chad Aalders]

I am trying to figure out which size hoosier r7 fits on a 10" wheel and the 282mm template. Anyone know

[Chad Aalders]

The 275/35/18 hoosier r7 tire on a 10" rpf1 wheels fits 282mm with tons of room to spare. Fyi. I should have seen if it fits the 266. There was a ton of room.