Champiro SX2 - different compound for 235 wide?
 

Looking into getting a set of SX2s for 17x9 wheels for HPDE. Most folks run 245/40R17, but 235/40R17 is also used. SX2 appears to be different in the 235 sizes (235/40R17, 235/45R17 and 235/40R18) - they are all marked as 200TW vs. the other sizes that are 260TW. The 195/50R15 (Miata size?) is also 200TW.

I only found one comment that someone experienced different results between a 225 and a 235, but no additional info.

Does anyone know why the different TW rating? Does it actually affect the performance of the tire on track? I'm looking mostly at low wear, communication and consistency over a hot session (no cooldown laps in the middle).

good catch. I already requested information to GT Radial. Lets see if they replay.

replay from GT Radial:
"Hello Fernando,
I can not offer specifics as to why the differences in TW rating but I can say at that moment there was a demand for the change. The change took place about 7-8 years ago now.
Tread wear ratings can affect the performance of tires. However, with ratings this close you might need to do multiple rounds of consistent testing to see how it effects the lap times of a particular driver. When doing this type of testing it is important to minimize all other variables as much as possible. Things like vehicle, wheels, air pressures, track temperatures and weather conditions all have an effect on the performance of a tire.
Let me know if you have any other questions we can help out with.

Best regards,

Edward Naranjo
Marketing Manager

GITI Tire (USA), Ltd.
10404 Sixth St.
Rancho Cucamonga, CA 91730
Email: Edward.Naranjo@us.giti.com"


no coments...

I'm surprised at how quickly they responded, but completely unsurprised at the lack of an actual answer. Fingers crossed someone ran both 260TW and 200TW in close sizes and can comment further.

I did find the post I was talking about. @BlueWhelan looks like you're still around, do you have some more insight on this perhaps?

Sounds like the 235/40R17 size (in 200TW) wore out faster and didn't handle abuse as well as the 225/45R17 (260TW).

I’ve had 3 sets of Sx2.

225/45/17 (200 tw) wore fine, consistent grip up to wear bar.

225/45/17 (260 tw) wore fine, consistent grip up to when I pulled them (2mm tread depth). Performance was pretty much the same to the 200tw.

235/40/17 (200 tw) wore fine like the rest up until 3mm tread depth, then fell off a cliff…in the middle of spring in SoCal. I can’t remember what date code they were…this was around 2018 so may have been old stock.

A current date code tire should be 260 tw, and should consistent across the range of SX2s. I wouldn’t worry about it. It’s possible I drove the tire when it wasn’t properly brought up from low temperature. This can affect the tire negatively, and since I daily drive that tire it definitely saw temps in the 40-30s. However, that wasn’t any different from the other sets I had either…

YMMV


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It was a quick, nonsensical reply.

Anyway, I’ve asked for more clarification—let’s see what happens.

The 86Cup / 86Challenge people found that the 18" 235 is significantly faster than the other sizes, it is the outlier.

Interesting. Even compared to 235 in 17"?

Yeah, if you browse around their FB groups you might find some posts.

@CSG Mikecould probably clarify better, but I think GT Radial believed they had a 200TW tire. The problem was it was 2+ seconds slower than every 200TW tire out there. After years of feedback from 86Cup/86Challenge and Im sure others, they changed the rating to something more proper in the 260tw it currently is.

The website lists the 200tw just from old stock but those really shouldn't be in anyones inventory at this point.

He answers the question pretty directly. Hey says that they put 200 on them because that's what the market wanted to see.

Treadwear is NOT a grip rating.

The 200TW mark is typically more for "classing"

I just bought a set of SX 245 40 17 for HPDE. Is there any recommended procedure for break in or initial heat cycling?

I just send them. Maybe take it a bit easier on the first session but the release compounds should be cooked out of them after that.