OFFICIAL Track Wheel and Tire Thread
 

Stock Wheel Data: 20x9 ET55, 20x12 ET47; F/R
Stock Tire Data: 245/35-20, 305/30-20; F/R
Wheel Weights: 24/26 lb; F/R (according to Forgeline)

Wheels - 20"

OZ Ultraleggera HLT - $3,050 - Available April 2014

OEM wheels - $12,006 (In Platinum, other colors more expensive)

GMG WC/130R - $?

Custom Wheels (Forgeline, HRE, Formula 43, Fikse, Finspeed, etc) - price varies, $3,500-10,000

Tires - 20"

Michelin Pilot Sport Cup 2 - $2,150

Pirelli Trofeo R - $2,326

Continental ContiForceContact - $1,954

Wheels - 19"

Custom Wheels (Forgeline, HRE, Formula 43, Fikse, Finspeed, etc) - price varies, $3,500-10,000

Tires - 19"

None with proper fitment at this time!

Popular tires that do NOT work:

(19") Nitto NT-01 - nearest front tire size over 1" too tall
(19") Hoosier R6 - nearest front tire size nearly 3/4" too short (treadless tires also not recommended by Porsche; may void warranty)

Notes:

997.2 GT3 RS front wheel offsets are not correct for 991 GT3 (47mm vs 55mm). They will fit in the fender wells, but may void warranty. 997.2 GT3 RS and 991 GT3 rear wheel offsets are within 1mm of each other.

This post will be updated with the information below.

Good idea, subscribing. Stock tires are almost 50% done after 1 wet and 1 dry track day, so this will quickly become relevant.

BTW, what about putting a smaller overall diameter tire on 19" both front and back, maintaining the same proportion?

GMG is offering a forged 20" set that looks badass. Does anyone know the weight of the wheels and the offsets? So far I've not been able to obtain this information. Thanks! -Tim

Trofeo R's 20" are available in the right size.
Finspeed is a very good wheel manufacturer. They can get you a forged 19" maybe even an 18" for steel brake cars. Well, not sure on the 18 but would be worth giving them a call.

I'm not aware of any 19's on the market that have the correct proportions, let alone the correct overall diameters. OEM tires are 26.8/27.2" in diameter, so the front to rear circumference ratio is 0.971.

That said, I don't see the point in investing in 19" wheels (let alone 18") right now.

How do the Trofeo's compare to the Dunlop SMR and Sport Cup 2 offered as OEM??

I've never driven them but if you search the 997gt2/gt3 forum you'll find a lot of info. Highly regarded there as a fast tire. Short life and expensive to purchase but fast.

Sweet. Thanks!

I don't think 18" will ever be an option since I've never seen track tires with 45 series sidewalls in Porsche sizes.

is it the ratio of replacement size to oem size not just front to rear ratio? Not sure if i worded that clearly.
Ringmeister, you're welcome. Good luck if you try them.

I'm not sure if I follow. What I'm referring to is the width of the sidewalls in order to keep the overall diameter of the wheel+tire the same as OEM.

overall diameter has to be no more than 4% different than oem? I think thats what i have heard on the 997 gt3 forum

F/R Diameter Ratios: Impact ABS, TC.

Overall Diameters: Impact ride height, tire contact patch, overall gear ratios.

There's no % "rule" - you should just be as close to OE spec as possible, since this is what the car's tuned around.

it appears right now best bet is run OEM wheels with trofeo at very high $$$