newport996

I should have clarified my earlier statement....on the rear, where all the weight is, you will notice the flex, thats where i notice it....enjoy the car!

jamie645

Why do you think contis suck?
I just put on a set of contisport 2s (n2) and I think they're great

Benjamin Choi

They suck because they don't grip nearly as well as the Pole Positions and the PS2s wet & dry. They're not even cheap. Poor value.

VGM911

In the absence of a clear consensus on this thread (and others), and as a result of doing as much reading as I could about N-spec tires, I ordered a set of 17" Michelin Pilot Sport Ribs today rather than a non N-spec tire.

I considered Bridgestone S-02As, but they're discontinued (although there is limited availability for the time being).

My fingers are crossed in the hope that these tires will be satisfactory.

jumper5836

I find it hard to believe people are feeling sidewall flex when comparing non N - N rated tires. You guys must have Star Trek Enterprise sensors on your ***. Or be doing something really hard on them obviously not being smooth like you would be @ the track.

I have just put on some cheap Kumho ECSTA SPT not N rated and these are twice as good as the Pirelli PZero N3 rated tires I had on before. I tracked them both and found the pzero decent but the kumho's are quiter and perform just as good if not better on the track and offer much better grip in heavy rain.

Tbred911

S02-A in 17" are N4 while the Ribs are N2... they are both great tires... can't go wrong with either... I hear the RIBS last a little longer as well... they are also more expensive than the N4 S02-A... on tirerack.com

Benjamin Choi

I heard the Ribs are amazing.

Star Trek sensors.... LOLOLOL

Tippy

Can't say about the PS2's but I agree 100%

BruceP

I'm sure you'll be happy. To me, you go with what Porsche says match the car best unless you have a specific, informed rationale for doing otherwise. The only people I think are completely crackers are the ones who don't know much about tires or suspensions, but are so confident that Porsche is lying through its teeth that they'd rather take their chances experimenting.

Benjamin Choi

Hey Bruce, regardless of whether your comments were pointed at me or not, it's not about a corporation lying to me and others who choose to make changes to the car.

You can do BETTER than what the the factory gives you. It's a part of the ownership experience - to make it yours.

And I do have fun teasing people about the choices they make to change-up some things on their 911s.

BruceP

Definitely agree with that, and my comment wasn't aimed at anyone in particular. I just think that with tires, a person should really know what "better" means before they riff on the program. It's a safety thing. Consider: N-spec tires are rated for, among other things, the added load on the rears. Putting tires back there that lack that reinforcement means that, at the very least, you're going to get some lateral flex under hard cornering loads. It seems to me that lateral flex in the rear under heavy cornering is about the last thing this car needs. So, imagine someone picks a tire that fits, is cheaper, looks good, and seems sticker. And it even has a nicer ride. And then one day they decide to push the car hard through a corner. The tires stick like they're supposed to, but the rear end keeps rotating for another few millimeters as the sidewalls flex... Given how high this car's limits really are, it seems to me there's no question that you're giving up bit of predictability, a bit of margin. Fine if you're a boulevard cruiser, but maybe not a good idea if you're going to push it.

If you're somebody who knows a lot about this stuff, maybe you can find some tires that are off the menu but still have the right properties to be a good match for this particular car. But if you're not and you're just guessing, then it seems to me that you're giving up some of that performance potential that you paid for when you bought the car.

Benjamin Choi

I'm using top notch street tires on my 911 in the rear like a good number of others on this board. PS2s. I think we'd all agree they're fantastic tires for the street.

So then the NSpec program fans are coming out saying there is a diff between N and non NSpec yet they've never ever provided any evidence as to exactly how they're different and even if they do have diff design/construction properties, they cannot/have not begun to explain how that impacts the drive on real roads.

Again, 315s don't come in N Spec since Porsche doesn't go that wide if ever (997 widebodies currently use 305s max width, no?) So am I going to run 305s because my 315s aren't N Spec? Am I leaving something on the performance table? Do I even care to split that hair?

So show me how v. going the way of Star Trek sensors funded by your fat wallets.

If they did make the NSpecs in 315s, I'd spend the extra $20 or so to say that I've got it and do it for some sort of peace of mind, but it'd be for just that... peace of mind, nothing more, nothing less unless someone can convince me why with facts/evidence/etc vs. anecdotal remarks easily placed in a casual, bloggable format.

My point is, if Nspec is available why the hell not it's only a few bux more. if not, don't sweat it. Just be sure you get some quality tires on there like the PS2s.

PS - I've recently had bad hopping issues with brand new PS2s - I'd check out the Bridgestone RE050A Pole Positions as well...

BruceP

Yes, maybe you are. Wider tires might look better, but they don't always mean better handling.

So, you're improvising on Porsche's thinking on a few levels, here: Your tires are wider than they had in mind. You've probably had to go to wider wheels so they don't crown. That means you probably had to mess around with the offset, or at least had to correct it. You may have added rotational mass. You've probably altered the point at which understeer transitions to oversteer, since it's unlikely that the change in adhesion front vs. rear was proportionally identical. You've added contact patch in the back, but may not have given yourself stiff enough sidewalls to cope with it. Up front, wider rubber has probably cost you some turn-in sharpness, and increased the tendency to tramline, which in turn could have you screwing around with alignment. And so on. All cool, if you know what you're doing.

For my feeble brain, that's too many variables to change at once and hope that the sum of it all is better performance.

VGM911

As I said when I started this thread, Porsche makes a persuasive and convincing case for using N-spec tires. There are those who follow the recommendations, and those who don't feel compelled to use such tires. I've enjoyed reading all of the opinions, both pro and con. It's been a healthy and productive discussion.

Porsche says:
"Porsche N-specification tires have been fine-tuned to meet the specific performance needs of Porsche vehicles. Tires branded with the Porsche N-specification have a unique combination of internal construction, tread compounding, and tread design. Using tires that are not N-specific or mixing them with other N-specification tires is not permissible."

Frankly, I like the guidance issued by the company and I've chosen to follow it. I also use Mobil 1 and Porsche's brand of antifreeze, and I follow their octane recommendations for gasoline that I buy. These products yield optimum performance and peace of mind.

When I go around a corner or an on/off ramp at high speed, I don't want to be thinking about whether or not I have the right tires on the car. Peace.

wross996tt

Here is some info on N-spec:
N-Spec
and here an actual comparison:

N spec comparison