There's a Reason for the 20-inchers
 

Now it all makes sense...

I was reading the Automobile magazine tonight that is highlighting the new models for 2012, and of course there was an article on the 991.

When it got to commenting about the new standard wheel sized (19 & 20), the article pointed out that Porsche moved to these larger sizes in order to fit LARGER BRAKES. That also includes 6-piston front brakes.

Not sure if it was known or obvious to all others, but it was an 'A-HA' moment for me. Not about the bling or anything other than Improved Performance.

Thats true.... that, and also the larger wheels dont make the car look as large as it really is because of the oversized wheel. the gt3 has 19" wheels and has 380mm rotors.
im not complaining, i love the 991. But, i dont love Porsche lying to us if what Automobile Magazine says is true.

whether it is technically necessary or not, it looks fantastic imho, esp. in the web special test drive. even a 997 looks better with 20", i would not care about the extra few lbs as long as someone isn`t going to the track very often.

The 20 inch Wheel and Tire package will likely be very close in weight to the 19s.
We found the same with the 19/18 comparison. The 18 inch wheels are lighter but the tires are heavier.
It is actually not difficult to make a 20 inch wheel setup weigh the same as the factory 19s. The fronts are 23.5 and the rears are nearly 29 lbs.

that´s good to hear, another reason to favor 20s.

Larger rotating mass=less performance.

u may have not noticed:

Tech1_Mike:
"It is actually not difficult to make a 20 inch wheel setup weigh the same as the factory 19s."

same rotating mass = same performance.
The only thing u could argue with is that a 20" set up would be a bit less comfortable.

Not saying what Automobile printed isn't true. It does make me wonder considering that my 2010 GT3 has 19s with 15 inch rotors and 6 piston calipers up front. The 991s rotors are smaller @ 13.8" IIRC; too small as a matter of fact relative the the 20" wheel, so I fail to see how the 20s make sense for brake sizing. The GT3/RS models would obviously be possible candidates for larger OEM brakes and/or aftermarket options, but not many buyers upgrade their brakes on a C2. I don't think Porsche would need to put 20s on Carrera to match what the 991 GT3/RS may have.

My Turbo has the Brembo BBK upgraded brakes on 19's . The standard Turbo OEM wheel would have fit without spacers . My HRE C20 needed OEM spacers .

The truth of the matter is that there is no single reason for the 20's. Many factors are involved including looks and brake size. It is not one reason or the other its both. They are optionsal so everyone is happy because if you want them great if not then thats great too.