DJF1

Guys you forget something VERY important. When you are talking about 911's you are talking about vehicles unlike any other in the market due to the engine location! The weight distribution is different. If you look at the tire rack the N designated tires often have DIFFERENT load characteristics and sometimes weight than non N tires of the same type and size. My take on this is that N tires truly are made according to Porsche specs, therefore will be different than a non N tire. Now if that is good or not its another topic all together. For me thought it does make sense to stick to N tires if the tire you choose has N designation tires available. Case in point the popular OEM tire from COntinental the Conti sport 2:
N tire:
225/40 ZR18
SL N2 (Porsche OE)
OE Fitments for This Tire/Size 280 AA A
1235 lbs. 51 psi 10/32" 21 lbs. 7.5-9" 8" 8.9" NA 25.1" 825

NON N:
225/40 ZR18
XL 280 AA A
1389 lbs. 51 psi 10/32" 22 lbs. 7.5-9" 8" 8.9" NA 25.1" 825

You can clearly see that the load on this front tire for the Porsche is 1235lbs where the stock tire is 1389. Also the weights are different. The N tire is lighter by 1 pound than the regular one ( 21 vs 22). So for sure these 2 tires are not the same in the construction! That is very significant as you can appreciate.

Bull

If they were truly made to a specific Porsche Spec, then every maker's tire(s) that claim N2 would have the exact same specs, right? That isn't the situation though if you look at all of the N2 rated tires in that size. The N2 rated Bridgestone Potenza S-02 weighs 22lbs, among other differences. The Conti Contact Sport is available in both N2 rated, and not N2 rated. If you simply choose the 88Y rated tire you get the same 1235lbs rating (on any tire), while choosing the 92Y tire will get you the 1389lbs rating reported above. There are many more examples of Nx rated tires having different specs, and non-Nx rated tires having the specs as the Nx rated tires.

BTW, tire examples from the same exact maker/model will vary in weight, as much as a pound, particularly when you are rounding to the nearest pound.

maurice97C2S

Dead wrong, I'm afraid ... the N designation will only change when a specific set of tyres is revised. A new approval will start at N0 ... so the number is absolutely not an indicator for contemporaneousness (pardon me George!)

cheers, Maurice

Bull

If you read my entire post...my point was that it is wrong also! All N2 tires are not made to a specific spec., which is why I used the "IF".

Anyway, my key point is that you can find non-N rated tires from the same maker that have the same specs as the N rated tire.

DJF1

I'm afraid you cannot speculate on that either. The reason why I placed one example in my post was to illustrate that indeed within the same size and type of tire there can be significant differences between the N and the non N. With that in mind then, what Tire Rack and Porsche say seems to true:
Therefore it is very possible that even tires seemignly been the same ( weight load etc) can have different compund ingredients and construction. Unless anyone has hard data on this , beyond what tire rack has, we cannot speculate so we must according to the other indications as illustrated with the Conti tire, assume that what Porsche states its probably true therefore beneficial for us to use N tires. Furthermore it is well known that on extreme cases like the Hoosier S04 at the 285 size which had catastrophic failures on stock 993's, the tire simply is unsuitable for 993's but for other front engined cars, or lighter cars in general there were not the same issues. That example for me illustrates the need to choose the right tire for the car. The N designated tires do offer for me that safety margin, so IF you like a tire that has N designations then its a no brainer really to get the N. If not then you take your chances to a certain extend, I would look at the load rate to ensure its comparable with the N spec tires at least when I make my choise.

Bull

If there is an N tire that you like, I would get it.

If you are looking for an R-Compound track tire, or a Slick, then the entire N-rating discussion is moot. The Hoosier example is one size out of many Hooziers, and one manufacturer out of many, who very successfully provide track tires. Somehow they do so without N-ratings!

Ray Calvo

Considering my early experience running Yoko A008 in the front (N-rated) and BFG Comp T/A in the rear (non-N rated) and getting severe oversteer at the slightest provocation, feel it's probably not a bad idea to run N-rated tires all round. Having spoken that, on the car now are (and my favorite overall tires) are the Bridgestone RE-750 (non-N rated). So, bottom line is, I won't be looking for the N-rating as a required criteria for me when I'm tire shopping, but will consider it a nicety.

Bull

Another question that comes to mind:

So, N-rated tires are "different" than those without the N rating.....how does one know if "different" is better, or if "different" was a design-to-cost/price exercise????? "Hey Klause, we don't need that 1389lb load rating for a rear engined car. Take it down to 1235lbs and give me your new price....OK, we have a deal, so slap that Nx rating on those tires"!

STLPCA

(1) Incorrect. An N rated tire may be exactly the same as a non N rated tire, IF the non rated tire met specs. In that case it is not different. Of course, there's no way to know for sure since in some cases there are significant differences between the rated & non-rated.

(2) We don't know if the N rated is "better" or just, as you suggest, cheaper. However, since there are a number of N rated tires that are NOT oem for new Porsches, & Porsche oem tires are generally high priced tires, I doubt the specs have much, if anything, to do with pricing. When you are a small volume car maker who advertises top speeds above 170 mph, the potential cost of a single tire failure dwarfs saving a few bucks, especially when those decisions are discoverable in litigation.

Buy N tires if you consider Porsche's stamp of approval important. If not, don't. It should be a personal decision since it's the buyer's life that rides on the choice. However, it seems to me it's a bit irresponsible & arrogant to suggest to others that they ignore Porsche's recs & accept yours when you bring nothing but speculation and conjecture to the table. From past posts, you know better.

maurice97C2S

Beautifully put, Dan. And at the end of the day, if you compare prices of N vs non N of the same tyre, the financial penalty of choosing N is negligible ...

cheers, Maurice (and I've just bought some non N tyres for track days !)

Bull

Of course it is "incorrect" in many cases....but, it is what was said, and I was saying "OK, if you accept that they are different....."

Actually, if you look at my previous posts in this thread, I HAVE said what you have said here. I was playing a little devils advocate with those who seem so sure that the N-rating makes tires superior, and trying to have others look at all of the possible angles. Sorry if I didn't make that sufficiently clear. Nowhere did I suggest that anyone ignore others and only take my recs. I asked a question. I guess some things, or people, aren't to be questioned around here!