wxseed

I just put Michelin PS2 on my 996 and they don't list "N" spec in the standard Porsche size for 18" rims ... I like the tires but am wondering if not being "N" spec has hurt the handling. In high speed corners when i pitch it through a highway on ramp, the car feels like it is moving around a bit. Maybe the softer side wall.....

AllanJ

Who are "they"?

Tire Rack has 235/40, 265/40, 295/30, 295/35 and 315/30 in 18" sizes that are N-spec.

Benjamin Choi

WAHAHAHHAAHA and good luck posing as if you can even begin to get your arms around all the factors involved in getting to any sort of conclusive evidence that running N-spec is faster.

some of you guys are so stuck in hairsplittsville it's absolutely comedic

jumper5836

C4S take 225/40ZR18 and 295/30ZR18
PS2 don't have N spec tires in 225/40ZR18

You probably could feel the softer sidewalls on the front, but if they are brand new tires. They need time to wear in. During that break in time the tires don't have much grip at all.

chago996

wxseed, I just replaced my old PS2 (rear, 2nd set) with PS2 again, and I feel the same looseness at the rear on high-speed corners. This will go away for the most part. They need about 1000 miles to break-in. Kind of crazy, I know, I'm on my 3rd set of rear PS2 and they are definitely worth it. The payoff is about 28k miles of life, and the looseness will get about 80% better as they get broken in at around 1000 miles. The other 15% will improve over time. At around 5-10k you will not be able to tell the difference. Mine is an '01 C2 with 84k miles and perhaps a C4 or C4S like jumper5836 has better weight distribution and torque transfer to the front that makes this sidewall flex less noticeable and perhaps "broken-in" sooner than a C2. My description is very unscientific, but based on 3 sets of rear non-N-spec'd PS2. My OE tire were the P-Zero, and they were cooked by about 8k and lasted till about 10k. Interesting how the Tire Rack does not list the service description (load index) of any N-spec'd tire. For what is worth, the load index of the PS2 on our size (265, 35, 18) is a 97Y (1609 lbs. per tire) while most non-N-spec'd are 92Y (1389 lbs). So it seems that the PS2 has a stiffer sidewall perhaps under compression, but that does not preclude that they can flex under side-load at high-speed cornering. But like I said, it becomes unnoticeable down their long-life road.

wxseed

"They are Michelin Canada, no N spec listed. They have Sport Pilot but not PS 2 in N spec ....

wxseed

Chago996, thanks for the info, I like the tires, far better than the P-zero's I replaced.

BruceP

Correct. They do offer, however, the same tire with two different load ratings. My indy put the XL tire on my car, and the sidewalls are marked accordingly.

I'm mystified. I'm a pro-N-spec guy, but the PS2 is so widely endorsed by Porsche folks... given nobody seemed to have anything to gain by selling me the wrong tire, I finally just accepted the story that the higher load rating version of the PS2 was as good as.

wxseed

Bruce p Thanks for confirming the Michelin status , I put the XL on my car, I figured it might be a better (stiffer) tire because of the increased load rating ... They also have a "run flat" but i stayed away from it ...

roberga

I don't get it. My PS2 18s are N rated. 235 f 285 r stock size.

BruceP

Me either. It really is odd. And odd that I was assured up and down that these XL rated tires were legitimate substitutes.

jury_ca

Benj, I'm not sure if your purpose is to parody a totally ****-expulsive, obstinate individual, but I'll take a moment and reply as if you're serious.

The argument is not so much whether N-Spec tires measurably affect handling vs. non N-Spec tires (they will), but whether your use of wider than factory rear tires will affect your handling balance. I hope you realize that one of the reasons that Porsche uses wider rear tires on the back of the 911 is to compensate for a RR car's tendency to oversteer? Hence, increasing the rear width of your tires, you have a car that is now increasingly prone to understeering. Throttle inputs at the threshold, will not affect handling dynamics the same way as the car is tuned to perform Furthermore, increasing the width of your rear tires makes your car more prone to aqua-planing, and we all know how much it rains in the Pacific Northwest.

So while terms like 'tire-slip angle' and 'polar moment of inertia' might make your eyes glaze like Chief Wiggum's at a Dunkin' Doughnuts, I wouldn't write off a whole body of Science as "hairsplitsville."

cdodkin

Great, now we have another religious war to add to the 'which oil do we use', which is best, Mac or PC genre......

BruceP

Please don't say the 'o' word...

nycebo