Ben8jam

I ordered Costco tires to fit OEM size on 1999 996 C2 with 18" rims. Website let me order, but when I got there, they said they technically shouldn't install them as not NO rated tires but if they did, they couldn't accept responsibility for what may happen. I agreed to move forward, as they could only find Cup tires with an N3 rating.

I've read the internets and there seems to be a huge flow of opinions of non NO or NO only. But I haven't found a definitive source that says why it does or doesn't matter. Some say NO tires are made differently. Or NO tires have different treads. But I'm having a hard time even finding how to find these tires online in NO rating.

So, are there more opinions on if I've a bad decision or should just drive speed limit for next few years?

hbdunn

You're fine. I haven't seen many people here use N rated tires. I believe they are the PS2 and a Pirelli Zero Rosso.

pulpo

There have been lots of threads about this but I'd love to see the responses in 2023. Personally, I've used both N rated michelin tires and non-N-rated michelin tires and didn't notice a difference.

Pure conjecture: It's mostly, if not all, marketing. With porsches they try to sell you "N0" tires. With audis, they try to sell you "A0" tires (regardless if your car is front or mid engine). With ferrari they try to sell you "K0" tires. The people who say that Porsche knows best must not have heard about the 10,000 oil change interval or the IMS bearing, right? I wonder which track tires have an N-rating. Those guys drive pretty fast. The whole thing seems bogus to me but I would still buy N-rated tires if they were available. Seems like the difference between brands/compounds/tread patterns must be greater than the difference between a MPS4S and an N rated MPS4S.

brontosaurus

you are already dead, having spun backwards into a ravine just for thinking about it. sorry!

168glhs1986

Cars aren't under warranty, run whatever you want. For the 992 GT3 RS with 1800 lbs of downforce, yeah I'll be running N rated tires. For my 996's I don't think it matters much.

Ben8jam

992 gtr rs....

(And hello Potomac MD! I grew up in Columbia and my father worked in Bethesda (I live in Cali now))

sasilverbullet

Not entirely marketing, watched a Porsche video about 13 years ago on the process behind giving the tire the N rating. What you're assured of with the N rating is that Porsche has tested it and it meets their requirements, not just on paper but at the test track in real situations.

Bottom line, you can get a tire without the N rating and it might be better than anything you've ever used...

pulpo

I am interested in learning more about this but it seems to be shrouded in secrecy. Overload of misinformation on the internet and hardly anything official that I can find. I think what you are saying makes the most sense. That the tires (make, model, and size) have been tested and approved by Porsche.

What I think is unbelievable is that there are physical differences between the tires other than the markings on the mold. It would require Michelin, for example, to have dozens of different production lines, or at least processes that they swap out for all the different manufacturers and in Porsche's case the individual models. Just doesn't make sense to me. But I would believe it if there were info from an official source.

TexSquirrel

As long as the load index is correct, you should be fine without N rated tires.
I really like my Michelin Pilot Sport 4S tires!

168glhs1986

don't be skeptical. It's a real thing. I was at Easton PA training center and asked Michelin and Porsche reps. The tires are made differently using different materials. With that said is it going to matter on a 996 that sees rain and street time? I'm no engineer but probably not.

Call PCA and they can probably provide the official Porsche answer for you.

168glhs1986

don't be skeptical. I was at Easton PA training center and asked Michelin and Porsche reps. The tires are made differently using different materials. With that said is it going to matter on a 996 that sees rain and street time? I'm no engineer but probably not.

Porschetech3

Well, I thought the same thing, but I heard it from the "horses mouth" that they are indeed "different". I was at the New Product Launch of the Cayman and there was a Top Level Michelin representative there and he explained the "N" spec vs ":non-N" spec and said there IS a difference...( for better or worse (?)) .

It's not about "marketing" it about "contracts".....and yes the contracts are long and somewhat complicated.

To put it simply ( not that it will end the debate) , if the tires are "exactly" the same it will be just another "N" spec tire and no reason not have the "N" on the tire, but if the tire is not "exactly" the same ( albeit rubber composition or tread or sidewall design or anything else) then it doesn't and cannot get the "N" spec unless a new "contract" is issued and it will get a new successive designation ie "N1" N2" "N3" ect....

pulpo

Very interesting. So, in practice, what this means is manufacturers go to tire companies and say, "we like X model of tire but we want it more of characteristic Y"? For example luxury carmakers could ask for extra noise cancelling? I think the question I would ask the tire manufacturers if I could is how different tires of the exact same model can really be.

I was curious so I went to the garage to check. Currently my rear tires are N3 MPS4S 295/30ZR18 and my front tires are MPS4S 225/40ZR18 and have a "CR" where the other tire shows "N3" which doesn't seem to be any type of designation.

jdbornem

You should run a test for us. Drive too fast into a sharp turn, and let us know which end lets go first. Then we'll know.

hbdunn

You are running a mix of 18" and 19" wheels? Trying to be a 992?

Also, maybe it's a GR and that's the Yaris spec?