I personally just didnt like the "style" of the 20s. The size wasnt bothering me. If they made my rims in a 20, I would have gotten the 20 incher.

 

Very interesting thread.

Just picked up my 5th Porsche. It's a 991 MT Base Cab. I went back to a base after having two S cars previously. All this talk about suspensions and tenths of a second etc. My favorite car was an 06 Base Coupe MT with just a couple of options. There is something to be said for simplicity. I personally never used any of the suspension settings on my S cars. I don't track so where am I going to take advantage of PASM. I would venture to say that a lot of you drive your Porsche like I do which is only on weekends when the weather is nice. Can any of you really tell the difference between a car that is 3/10's of second slower than the next on city streets? I don't know about the rest of you but where I live there are cops everywhere with radar just itching to pull over a person driving a 911.

My new Cab rides and drives just great! From a quality standpoint it's light years ahead of my previous cars. The new 991 in any form is just fantastic IMHO. In the January issue of Motor Trend on page 66 they say quote "Our 911 fanboys were, however quick to pick a favorite, and nearly everyone preferred the base 911 to the Carrera S".

I could be wrong but like I said before there is something to be said for simplicity!

 

Spourreza-love your wheels too. The sport design wheel option on the S (see docmalone's pics) come real close so I'd take those if I go w/C2S.
Gjnockie-fantastic comments! I know I'm getting to the splitting hairs point in my analysis and I found your post to be particularly interesting because you've has an S and I think my driving will be more like yours. I'm just trying my best to avoid any "regrets" by not spending an extra $10k. No doubt the C2 is more than enough car for me 95 percent of the time. It's just that other 5 percent that has me wondering...

 

I could not agree more. However in this specific case of PASM functionality, if your previous S car was so equipped, it was providing you with a very compliant ride and firming up automatically while taking fast corners, even if you did not "use the suspension setting". Whether this COOL functionality is worth the cost (not really an issue in my case), future out of warranty repair requirements (somewhat of an issue in my case), lowered ground clearance (even more of an issue), adding complexity to a system with marginal gains (and they would be marginal if I am not driving this car at the limit) is at the heart of the discussion/ dilemma from my perspective. In other words, I have acknowledged that PASM is better in theory, but is it that much better in practice to outweigh my other concerns? I will find out for myself soon enough.

 

Even though a part of me likes the carrera classic wheels, I do agree the 19 inchers look very good. They have a very timeless way about them. Their thin-ness on the outer surface ( since the width of the spokes is in the depth) make them very hard to photograph and look good in pictures. In person, I agree they are spectacular.

 

My previous car was a White 09 997.2 S Coupe PDK as you can see by my current Avatar picture. Haven't had a chance to change it yet. It was equipped with PASM. Personally I hated the way it handled and rode when Sport was engaged. On city streets the ride was too firm, choppy and non compliant and I felt it handled better with it off. I never noticed my 09 being able to "firm up automatically" when driving in a spirited manner. With it set to normal the ride IMHO was no way as smooth as my new car. 991 handling is better in every way compared to my 09.

Another consideration (as has been pointed out) is if you plan on keeping your car long time are the potential repair costs. I can only imagine what a set of new shocks cost for a PASM equipped car versus a standard suspension car.

Don't get me wrong. The S is also a fantastic car. If you need the speed and you intend on tracking the car or you have an aggressive driving style then by all means... go for it!

How many of us are really capable of exploiting the full potential of a 911 anyway?

 

How does that work? 1" in diameter translates to half an inch of tread depth, doesn't it?

 

My last car is also a 09 997.2 C2S cab with PDK. Compared to 997.1, the sports mode of PASM has improved quite a bit, but as Porsche noted, it's really designed for track use. Also, in order for the automatic firm up to kick in, you have to be driving fast with a lot of lateral G. I experienced it while on freeway fast sweepers (80mph+) a few times. I agree that 991's PASM has completely eclipsed 997.2 in terms of handling and compliance.

And, if you really want to see the full potential of your car, sign up for a track event. You will be amazed, have fun, and actually improve your driving skill as well.

 

If that's a picture of your 2012 991 Cab... I have the exact same color combo!

You have good taste!

 

Even better, sign up for Driver Skills or Autocross. The higher speeds and increased risk of track events keeps most people from going anywhere near the limit (and a good thing too!) but the same people at DE or Autox where speeds are mostly 1st/2nd gear with damage risk limited to hitting a cone are much more able to push hard enough to squeal and slide and therefore learn how the car responds. I don't know if a lot of regions even have Driver Skills, but as a DE Instructor its always obvious which students are novice and which have been to Driver Skills. Hugely worthwhile investment.

 

The question at the time was whether 20" wheels would be more subject to damage because of less rubber between the rim and the road; and collaterally whether they would be less comfortable and louder. That is the usual case when we go up an inch in wheels using the aftermarket. It is not so when the factory does it for us.

This is why. An aftermarket wheel must be accompanied with lower-profile tires to keep the overall diameter of wheel and mounted tires the same. Otherwise the tires rub the fender, the speedometer is wrong, and the various stability control systems go nuts because the rotating speeds are wrong. A factory decision to offer both sizes is different. Our computer has a setting for "19 or 20 inch wheels?" That takes care of the computers, including the speedometer. (Speedometers don't measure speed, remember. They measure rotations of the wheels per second. A little arithmetic gives the speed, but it relies on knowing the overall diameter.Thus our speedometers change in accuracy as the tires wear. We're going slower than than the calculation reports. Thus Porsche speedos say 60 when we're doing 59 with new tires, but it gets to 60 when we're doing 58 or even 57 when the tires are due to be replaced.)

So with a setting to deal with the diameter problem the factory simply allows two different overall diameters. The 20's are bigger than the 19's overall, so the tire thickness, the section height we say, can be the same with both. Not exactly, but it's close. As Chuck911 said, dig up my earlier post if you care that much, but basically the answer was "it's trivial". Something like 8mm in front and 11 mm in back, but do check if you care.

That also means that with more overall diameter and the same section height, the 20's are quieter and more comfortable than the 19's under the same conditions. People who observe otherwise in a quick road test are noticing differences in conditions, viz specific road section where they think about tires instead of other observations, the tire models on each car, and so forth. I feel pretty confident asserting that from theoretical considerations since I was just discussing it with the Michelin rep to PCNA and their practical tests say the same thing. The only aspect that might go in favor of the smaller tire is the resonant frequency of the tire cavity volume or the tread frequency, and Michelin specifically design to avoid either issue, as do Pirelli and Bridgestone I'm sure. A third-party brand might not be so well designed of course.

Pick the ones you like esthetically. Don't fret these other issues unless the slightly better comfort levels with 20" wheels are important.

Gary

 

 

Agree completely. Good post.