Trying to Understand Tire Sizes

[jjjaroscak]

So I’m hoping to put some good track tires on my stock 19” rims, but since no one sells anything good in the stock 245/50 size I’m trying to figure out what sizes will fit.

So the stock rims are 19x8.
Width in millimeters is 203.2 which is much smaller than 245 (9.64567 inches).
Height in millimeters is 482.6.
Height of stock tires = 482.6 + (245*0.5) + (245*0.5) = 727.6 (28.645669 inches) correct?

So why is the width of the tire so much wider than the width of the wheel? How big/small of a tire could you safely put on an 8” wheel?

Assuming I didn’t care about keeping the same tire height could I put any tire with a width between 205 and 245+?

I’ve found some Nitto NT05s in size: 245/40R19 98Z, would these fit and be safe to use on the 19x8 rims? What other sizes can I use?

[SSMickey]

Check out this thread about tire size. Should help answer some of your questions.
http://www.camaro5.com/forums/showthread.php?t=62838

[oldfriend]

Originally Posted by jjjaroscak

So I’m hoping to put some good track tires on my stock 19” rims, but since no one sells anything good in the stock 245/50 size I’m trying to figure out what sizes will fit.

So the stock rims are 19x8.
Width in millimeters is 203.2 which is much smaller than 245 (9.64567 inches).
Height in millimeters is 482.6.
Height of stock tires = 482.6 + (245*0.5) + (245*0.5) = 727.6 (28.645669 inches) correct?

So why is the width of the tire so much wider than the width of the wheel? How big/small of a tire could you safely put on an 8” wheel?

Assuming I didn’t care about keeping the same tire height could I put any tire with a width between 205 and 245+?

I’ve found some Nitto NT05s in size: 245/40R19 98Z, would these fit and be safe to use on the 19x8 rims? What other sizes can I use?

Can you just understand , that the rest of the Country works on SAE , not Metric

[OmniCamaro]

And this: http://www.tirerack.com/tires/tirete....jsp?techid=46

Tirerack.com has tons of info!

[jjjaroscak]

Originally Posted by SSMickey

Check out this thread about tire size. Should help answer some of your questions.
http://www.camaro5.com/forums/showthread.php?t=62838

I did read this, but those are recommended tire sizes to keep the spedometer as accurate as possible. But as I stated I haven't found any good track tires in the suggested sizes so I want to know if I can safely put other size tires on the wheels.

So unless there is more to it in the later pages that I missed it doesn't really answer my questions.

Originally Posted by OmniCamaro

And this: http://www.tirerack.com/tires/tirete....jsp?techid=46

Tirerack.com has tons of info!

This is actually what I read trying to figure this all out which made me understand all the numbers but I just wanted to make sure there wasn't something I was missing.

This article is good at explaining what the numbers mean but other than wheel diameter it doesn't explain what tires go on what wheels. It doesn't explain why the tire width is so much higher than the wheel width which is my main concern/lack of understanding.

[OmniCamaro]

Originally Posted by jjjaroscak

I did read this, but those are recommended tire sizes to keep the spedometer as accurate as possible. But as I stated I haven't found any good track tires in the suggested sizes so I want to know if I can safely put other size tires on the wheels.

So unless there is more to it in the later pages that I missed it doesn't really answer my questions.



This is actually what I read trying to figure this all out which made me understand all the numbers but I just wanted to make sure there wasn't something I was missing.

This article is good at explaining what the numbers mean but other than wheel diameter it doesn't explain what tires go on what wheels. It doesn't explain why the tire width is so much higher than the wheel width which is my main concern/lack of understanding.

Go to the following link and find the exact link that you think might explain what info you're looking for. Like I said before, there is a ton of info on their site! Just trying to help you out. I have it bookmarked for reference when I have a question on tires.

http://www.tirerack.com/about/techcenter.jsp

[jjjaroscak]

Originally Posted by OmniCamaro

Go to the following link and find the exact link that you think might explain what info you're looking for. Like I said before, there is a ton of info on their site! Just trying to help you out. I have it bookmarked for reference when I have a question on tires.

http://www.tirerack.com/about/techcenter.jsp

I would have assumed the Tire Size Guide would have it but it does not.

What is the relationship between wheel width and tire width? It clearly isn't 1 to 1.

Will a 245/45R19 tire fit on a 19x8 wheel?
Will a 245/40R19 tire fit on a 19x8 wheel?
Will a 275/35R19 tire fit on a 19x8 wheel?
Will a 225/40R19 tire fit on a 19x8 wheel?

[jjjaroscak]

Would these RS3s fit? http://www.tirerack.com/tires/tires....2140&tab=Specs
Size: 245/40ZR19
Sidewall Style: Blackwall
Serv. Desc: 94W
UTQG: 140 A A

[JimE]

use tirerack.com

pull up the tire in question, and goto the "specs" tab. it lists the recommended wheel width

[JimE]

the same page you linked, there is a "rim width range" column

just note that at the small end of the range, the sidewall will bow out, and at the large end of the range, the tire will be stretched. so you will want to stay in the middle of the range

[OmniCamaro]

Originally Posted by jjjaroscak

I would have assumed the Tire Size Guide would have it but it does not.

What is the relationship between wheel width and tire width? It clearly isn't 1 to 1.

Will a 245/45R19 tire fit on a 19x8 wheel?--245mm=9.6in.
Will a 245/40R19 tire fit on a 19x8 wheel?
Will a 275/35R19 tire fit on a 19x8 wheel?--275mm=10.8in.
Will a 225/40R19 tire fit on a 19x8 wheel?--225mm=8.8in.

245 is mm / wheels or rims come in inches, just convert either way. There's an app for that, lol. No seriously there is, I have it. "Convert units" is the one I use!

[jjjaroscak]

Originally Posted by OmniCamaro

245 is mm / wheels or rims come in inches, just convert either way. There's an app for that, lol. No seriously there is, I have it. "Convert units" is the one I use!

Yeah that's what I did. What I don't get is why the stock tires are 9.6 inches and the stock wheels are 8 inches. Why is there a 1.6 inch difference? Is it recommended the tires be wider?

[OmniCamaro]

Originally Posted by jjjaroscak

Yeah that's what I did. What I don't get is why the stock tires are 9.6 inches and the stock wheels are 8 inches. Why is there a 1.6 inch difference? Is it recommended the tires be wider?

I really have no idea man. As a total guess, maybe when manufacturers measure wheels/rims they don't account for the lip? That's only a guess, I'm sure there are experts on our forums that could provide the correct answer.

[jjjaroscak]

Yeah, from what little I've gather I'm going to go with a tire with the same width unless someone tells me otherwise.

Hankook Ventus R-S3:
http://www.tirerack.com/tires/tires....2140&tab=Specs
Size: 245/40ZR19
Sidewall Style: Blackwall
Serv. Desc: 94W
UTQG: 140 A A