0corvette-wheels.com

We contacted Pirelli today to verify the specs on their Pzero Nero 375/20-21 tire, and although a tire calculator will tell you that it "should" have a 14.74" tread width, it doesn't. they said they are NOT supposed to be on ANY wheel wider than 13"!!!!

It is very deceiving, so we put a recommendation into their suggestion box, saying that they should either change their size to a 345-355/20-21 (correct sizing), put a disclaimer on their website, and/or at the very least, put the actual specs on their website, so people stop "assuming" they are really 375mm and stretching them onto 13.5"+ wheels as this can be unsafe! Let's see if they say/do anything about this moving forward...

This is a BS marketing gimmick if you ask me... in the meantime, Kumho Ecsta SPT's come in a 375/20-21 and they fit up to 14.5" (as a 375/20-21 should!) Not the stickiest tire in the world, but plenty of contact patch/meat for anyone wanting a HUGE, cheap tire! (Currently back ordered, but $249 ea. when they are available)

TriniJoe

Good to know, I ordered 13.5" wide rims to fit those tires. Now I may have to go with the Kumho.

TriniJoe

I sent an email to Pirelli about the tire fitting on a 13.5" rim & below are Pirelli statements. What to believe?

Subject: RE: Nero 375/20-21
From: PTNA - Consumer Affairs, US <consumer.affairs@pirelli.com>
Sent: Apr 1, 2010 10:22:29 AM

We apologize for the delay. The person that usually answers email has been out sick.
The approved rim range is 13"-14". And yes, it will fit a 13.5" wheel.

Pirelli Tire North America
Consumer Affairs

0corvette-wheels.com

That person who replied to you should be fired. They are NOT approved for 14" wheels. Google / Search the tire size "375/20-21" and you will see a Z06 and some others with 13.5" wheels wrapped in these tires. The sidewalls are severely stretched to fit. The max I was told was 13" and after seeing them on the 13.5" wheel, I would say a 12.5" is the perfect size for it. It simply isn't a 375mm width. Call and ask for a tech.

0FORGED DST

According to the 2010 Pirelli product catalog in my possession

Item # 1825700 375/20R21 XL 103Y approved rim width 12.0 to 13.0

Accordingly, this tire meets any and all Corvette requirements in regard to dimensional data, speed rating, and load rating. You couldn't buy a better tire. The rim width data WAS changed from the 2009 Specs where they listed 13.0 to 13.5 as the recommended range of width. So 13.5 is absolutely NOT approved for this tire.
I hope this clears up some questions, I have very good friends at Pirelli...

0corvette-wheels.com

Jerry,

Maybe you should call your very good friends at Pirelli, and ask them why their 375mm tire isn't really 375mm? That was the point...

For anyone trying to put them on wider-than-13" this could be dangerous... which some have... based one a "mathematical equation" figured out by any tire calculator, it should fit a 14-14.5" wheel... so being that they have never released a recommended size range, on their site, nor TireRack's, or anyone else's that Ive seen that carries them... one could only "assume" based on a tire calculator that it "should" fit a 14" wheel... or a 13.5" at the very least... but it can't - why? because its NOT A 375mm TIRE!!! (to Pirelli, not you )

PS - When you talk to your friends over there, ask them why there head tech was DUMBFOUNDED when I called (same day I posted this thread)

0FORGED DST

As I said I have the 2010 PUBLISHED Pirelli data book in my hand......they recommend tire width 12.0 to 13.0 NOT anything larger than a 13 so a 13.5 is NOT recommended. Last year they published in their PUBLISHED 2009 product catalog 13.0 to 13.5 ...so it has been changed just as I said. I was trying to clearup misinformation on this open thread. Section width and tread width are not the same thing. Maybe you could ask Tire Rack and other's why they don't have this published recommendation but I do. You can come by and see my Pirelli product data books whenever you want....no charge. I always try to stay up to date on anything happening in this business as you well know.
We try to sell wheels, not promote tire brands so I am only informing our mutual friends on the forum regarding what may be a misconception caused by this thread. I am not the Pirelli tech line,I'm just trying to be helpful.

0corvette-wheels.com

I'm not sure what could be "misinformation" you only verified what I said in the very first few lines. The tire is not good for anything over 13"... the whole point was the "375" # they labeled the tire with. Its VERY deceiving as it not REALLY a 375mm tire. Get it?

And although you DONT sell tires, WE do, so why are you in my thread again!!!

0FORGED DST

Because I was giving useful information about the fact that they HAVE changed the recommended size range for this size tire to a maximum of 13.0 Which supports what you were saying. I talked to Pirelli at the Homestead race last month about this tire, and they sent me the first acknowledgements, in print that they had changed the technical data on this size as well as telling me some of the reasons why. But that's a story for another day.
Now I'm out of this thread.........

jerry

0corvette-wheels.com

THEY NEVER HAD a recommended size listed, so what's to change? what they REALLY need to change is the SIZE! It's not 375mm... wow, over your head six times now...

0FORGED DST

Recommended sizes listed since Dec1, 2008. Pirelli product catalog given to authorized Pirelli dealers and tuners at SEMA show in Nov., 2008. You probably missed it.

Luweegy

I'm gona get some airshocks and see if I can get some 26" suv wheels under mine.