Guys I could use some help here. I am looking to have a set of forged wheels made for my car. I am looking at 9X20 and the rears at 11X20 right now. Should I be looking at a 12 inch rear wheel instead? I just got a set of Michelin SS about 3500 miles ago in factory sizes but If I go with new rears in a 315 or 325 if needed. I see the MPSS is a 315/35/20. If so, should I run a 315 or 325? Any issues with the AWD?

Should I go with the factory offset or use something different/more aggressive?


The factory wheels information is listed as:

8.5Jx20 ET51
11Jx20 ET56

http://www.wheel-size.com/size/porsc...-turbo-38-eudm


Thanks for the input guys.
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The TTS has 11.5" wheels on the rear with 56 offset, the same offset as the TT. Therefore I would be looking at 11.5" as a minimum. I have seen ads for 12" in the rear but I don't know if that has any fittment problems.

 

Thanks Jim. As of now im going with an 11 but more aggressive offset to push the wheel out slightly and still retain use of the factory size 305/30/20.

The goal is have ave the car drove like factory and also continue to use MPSS that are available readily.

If i go to a 11.5 wheel would sticking w the 305 be fine?

 

Since most of us are looking to run the widest wheel possible, I would recommend using a 12" wide rear option. It's a personal preference though, because since you purchased replacement tires prior to the wheels, you may want to consider the smaller width to accommodate the tire better.

I would recommend a more aggressive fitment than stock, that's for sure.

 

Jurrian, I really appreciate the guidance. I definitely will be going with a more aggressive offset. I just do not wanna mess with the ride and wont be lowering the car.

The 305 I would imagine would be stretched on a 12 inch rim and not sit right? Would an 11.5 be a good compromise?

Also do your wheels typically fit factory center caps ? Or do you use your own so that you can remove more material thus making the weight of the wheel lighter?

 

305/30/20 would be stretched a bit on a 12" which is why I would recommend the 11.5" as you mention, that is indeed a good compromise.

There are a few center cap options, and the majority of them will accept an OEM Porsche cap, there is no problem there, we can machine the wheel to accept the same OE sized cap, but make sure to double check and ask again when you have your wheel selected so we can verify that again for you. Weight difference between machining a wheel for an OE cap vs Our Cap is pretty insignificant.

 

The 2014-16 TTS has 11.5" rears with 305 tires, the TT has 11" rears with the same 305 tires so your good with either choice. The wider wheel on the TTS helps fight tire deflection during high G turns. Porsche has done this for years on numerous models.

 

And for one more data point the 991.2 TT has moved up to 11.5 inch rear rims.

If you pull up the tire specifications on tirerack they have a recommended rim width range for each tire size. As mentioned, Porsche seems to tend towards the largest recommended rim width.