Section Width v. Tread Width
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From: The High Mountains of North Texas
Section Width v. Tread Width
I learn a LOT on this forum. 
I did come up with something that Something I have learned about and DIDN'T read about on here, after doing lots of research, so thought I'd offer it up to help others in the future. Just paying it forward.
It's an easy thing to say "I have a base Vette, I want to run ZO6 size skins, without doing the widebody." Lots of folks, including me, have chased this rabbit. Looking at just the rears, going from 275 to 325, everyone said I'd need bigger rims, like 11", with near perfect offset. CCW is of course the most named source for that perfect offset. I chatted with the folks there, and one interesting thing they told me was that even with their wheels, I could run SuperCars OK, but that PS2s were iffy, as they were "bigger". How the heck could they be bigger if they are the same size?
I've now had the big SCs for a while, and yes indeed they are snug under there. While looking at tires on Tirerack, I saw that while all the 325s had the same "section width", they varied a lot on "tread width". What they heck was the difference? Turns out, section width is basically how fat the tire is, at its widest, once the tire is mounted and sitting under load. And THAT is what they are referring to as "325", its the section width (typically halfway up the sidewall), NOT the tread width. And it is the tread width that controls what will fit under the fender.
And then looking at the tread width (under "specs" in Tirerack), one sees that the SCs are the narrowest tread, at 11.6", while the PS2 are at 12.3", 2/3 of an inch wider! No wonder they handle better for the same "size", as they have more than 5% more tread on the ground. AND, that they are a tougher fit to get under there.
So in fact, what I REALLY want then, is the most tread I can get under there, regardless of what the section width is. Digging around through TR, I came up with the Yoko Advan NEOVA AD08, in a "295" size, that has a tread width of 11.5", virtually identical tread width to the 325 SCs. And, it will fit on the factory size wheels, 10". A set of these on the rears, with the 255s on the front, I believe are going to be my next track tire set. There may be others that would fit this bill as well, I'm sure I haven't research every possible tire yet.
I'd sure be curious to know what the 285 sized PS2 have for tread width.
It is interesting that tread widths are not reported for lots of tires, including things like Nittos. So I may have to hit some of the local get-togethers with a tape measure and crawl around a few cars.
Anyway, if you want to run factory ZO6 width tires on a base car, there are alternatives to spending money to upsize the wheels first. The things you learn.
For what its worth.
I did come up with something that Something I have learned about and DIDN'T read about on here, after doing lots of research, so thought I'd offer it up to help others in the future. Just paying it forward.It's an easy thing to say "I have a base Vette, I want to run ZO6 size skins, without doing the widebody." Lots of folks, including me, have chased this rabbit. Looking at just the rears, going from 275 to 325, everyone said I'd need bigger rims, like 11", with near perfect offset. CCW is of course the most named source for that perfect offset. I chatted with the folks there, and one interesting thing they told me was that even with their wheels, I could run SuperCars OK, but that PS2s were iffy, as they were "bigger". How the heck could they be bigger if they are the same size?
I've now had the big SCs for a while, and yes indeed they are snug under there. While looking at tires on Tirerack, I saw that while all the 325s had the same "section width", they varied a lot on "tread width". What they heck was the difference? Turns out, section width is basically how fat the tire is, at its widest, once the tire is mounted and sitting under load. And THAT is what they are referring to as "325", its the section width (typically halfway up the sidewall), NOT the tread width. And it is the tread width that controls what will fit under the fender.
And then looking at the tread width (under "specs" in Tirerack), one sees that the SCs are the narrowest tread, at 11.6", while the PS2 are at 12.3", 2/3 of an inch wider! No wonder they handle better for the same "size", as they have more than 5% more tread on the ground. AND, that they are a tougher fit to get under there.
So in fact, what I REALLY want then, is the most tread I can get under there, regardless of what the section width is. Digging around through TR, I came up with the Yoko Advan NEOVA AD08, in a "295" size, that has a tread width of 11.5", virtually identical tread width to the 325 SCs. And, it will fit on the factory size wheels, 10". A set of these on the rears, with the 255s on the front, I believe are going to be my next track tire set. There may be others that would fit this bill as well, I'm sure I haven't research every possible tire yet.
I'd sure be curious to know what the 285 sized PS2 have for tread width.
It is interesting that tread widths are not reported for lots of tires, including things like Nittos. So I may have to hit some of the local get-togethers with a tape measure and crawl around a few cars.
Anyway, if you want to run factory ZO6 width tires on a base car, there are alternatives to spending money to upsize the wheels first. The things you learn.
For what its worth.
