Porsche Jeff

Sorry if this has been covered already. I have a 2012 991 Cabrio (base). Need to replace my rear tires. I have Carerra classic wheels 20". I want to go from the stock 295's to 305's. From some of the other posts, it appears I will have no proiblem getting them installed?

991 mavens can you chime in? Thanks for the help.

2001f4s

No, it should not be an issue going from 295 to 305's

Jvmorrow

A newbie question. What are the benefits of going from 295 to 305? I have about 2k left on my rears.

LexVan

Jeff, make sure you can obtain the 305s. They were in very short supply last year. Michelin and Pirelli, both.

LexVan

For the everyday 991 driver, it's more about appearance. The 305 looks a little wider from the rear.

From a performance standpoint, i think you'd need to be a highly skilled driver, wringing out the car, to really notice.

305s;

Cost more
Weight more
Harder to source
Less selection

Jerry991

There is no significant benefit other than some people feel that the 305 looks better. Problem is the Michelins are extremely hard to find so have to settle for 295s if want Michelin which I did.

991carreradriver

If you have the 5mm spacers, the 305's are not recommended by Porsche.

STG

So 305's on an 11" wheel?

Does the sidewall profile look any different whether a 295 or 305 is used on an 11" wide wheel?

LexVan

Are you sure? IIRC, the only time Porsche made that recommendation (from their on-line car config.) was when the Sport Techno wheel was selected, since it is already a 1/2 inch wider.

Jnosol

Also less tire feel. Porsche like to stretch their tires for better sidewall feel. However, 305 does look meatier.

Example, my M5's rear wheels are 10" wide using 295. 991 equipped with 11" are using 295". GT3 puts 305 on 12" wheels while non-GT cars run 305 on 11.5".

Michael_s

I had factory 5MM spacers and 305's on my C4S. Seems like they recommended it to me.

Jnosol

If your 991 came equipped with 305, then you have 11.5" wide wheels. If it comes standard with 295, then you have 11" wide wheels.

C2 Rear Setup
11Jx20 ET70 (295)
11.5Jx20 ET68 (305)

C4 Rear Setup
11Jx19 ET67 (295)
11.5Jx19 ET50 (305)

Jvmorrow

I am coming up on replacing my PZeros and searched the forums on the MPSS. I found these tires but they are not cheap and maybe overkill for me not using the car on the track.

Question: Do they make the N rated MPSS tires or only in the Cup version?


Michelin Pilot Sport Cup 2Not Yet Rated | Reviews (10)
Click to Compare
MICHELIN
PILOT SPORT CUP 2
Streetable Track & Competition
Front: 245/35ZR20 (91Y)
N0 Porsche
Sidewall Style: Blackwall
UTQG: 180 AA A
Qty:Per Tire:

2
$472.00
Availability: In Stock
Can be delivered Thu, 05/19 to 33304 for $19.22 per tire.
Rear: 305/30ZR20 (103Y) XL
N0 Porsche
Sidewall Style: Blackwall
UTQG: 180 AA A
Qty:Per Tire:

2
$469.00
Availability: In Stock
Can be delivered Thu, 05/19 to 33304 for $34.18 per tire.

LexVan

Cup 2s. Great tires. Expensive. Overkill unless you plan to DE. <1/2 the tread life you currently enjoy.

RobC4sX51

Your looking at S vs base wheels. All 991S' (rwd or awd) came with 8.5"x20 front and 11"x20 wheels with different offsets in the rear as you point out. They put 295s on the NB and 305 rear tires on the WB cars. Just saying. The GTS and some special wheels (Fuchs and Sport Techno) had even wider front (9") and rear (11.5") wheels. These wheels always have 305s even if on a NB.