Hi Guys,

I just went to the dealer to pick up my car after swapping out the Pirelli P Zero's for Super Sports. The factory tires are 245/35/20 for front and 295/30/20 for the rear. When service ordered the new tires we went up to the 305/30/20's in the rear.

I went to pick the car up and several other 991's were in the drive and as I approached the car it looked like ****. The tires don't fill the fender wells and the spacing between tire and fender looks ridiculous. It’s literally the different between two fingers with the stock pirellis with the car next to mine and the New Super Sports are 3-3 and half fingers. The fronts do not look right either. The tires look more recessed into the fender wells too.

I left the car at the dealer and kept the loaner as it was closing in on 7 pm tonight. I will head down and speak with the guys in parts tomorrow when they are in on Saturday. I wish I had taken a picture but it was dark.

I switched all four tires due to going with Super Sports but in reality my oem fronts still had plenty of life. I had just crossed 10xxx miles and the rears were shot. If i go back to the Pirellis i could throw my fronts back on and just get the two new rears. My preference would still be to go with the michelin, but the correct size.

Any recommendations here? I am not a tire guy and could use the help.

 

If you're worried about tire life, the Michelins are a good choice. Me, I'm going to the Nitto Invo's. Sticky as hell, best tire in the rain, but 5K and they're shot!

 

Yeah the tire life is one reason but I have had great luck with the super sports. They are better in the rain than the oem tires as well.

 

Strange situation. What does Tire Rack say about the diameter and width difference?

 

I have PSS 255-35-20 & 305-30-20.
I assure you the rears are significantly wider and slightly taller.
However, my wheels are .5" wider which adds .2" extra to the tire section width.

I sold my CSIII wheels, because, like you say, they are undersized.
Thats why everyone adds spacers.

My suggestion is keep the rears, because its your imagination thinking they are smaller than the OEM tires.
Then change the fronts to 255-35-20.
245 is to small and probably done on purpose to dial in understeer.

PSS do have flatter sidewalls than the bulgy sidewall PZeros.
That is what is playing tricks on your eyes.

Check out the pics in my post.

 

Post?

 

I was on mobile, so could not post the link earlier:

https://www.6speedonline.com/forums/...ion-width.html

 

so if you switch the Pzero factory 245/35/20 front with the MPSS 245/35/20
the ground clearance gets smaller? i have a driveway problem

 

LunarX--is not the width that is the issue. I think spacers would fill out the depth of the fender better but the height/circumference of the tire. This would be off because looking at tire rack it says both are 27 inches. Without posting a pic I sounds like a nut but the space between the tire and fender is wider, which makes the car look odd.

It is the sidewalls that look off. It makes it look like the car is four wheel drive.

 

what are MPSS 245/35/40? :-)

 

Ha the fronts are still 245/35/20's

 

I get what you are saying.
You need to realize, Porsche is using stretched fitments on the 991.

The typical wheel width for a 295 is 10.5"
For a 305 it's 11".
So 305 is a better size choice if you want to have a squarer sidewall.
You did that, and you now have a wider tire.
Your eyes are playing tricks on you, if you think otherwise.

The specs are;
Section Width: 11.8" PZero-295 vs 12.5" PSS-305
Diameter: 27" PZero-295 vs 27.3" PSS-305

Note: the PZero SW spec is adjusted by +.2, because it's on a 11 instead of the "measured on" 10.5".

Look how much difference there is.













For the front, something very similar is going on.
I up-sized to a 255 and I barley got any section width increase.
So I hate to imagine how bad a 245 would look.
So go 255 on the front, if you want a squarer looking sidewall.

The specs are;
Section Width: 9.8" PZero-245 vs 10" PSS-255
Diameter: 26.8" PZero-245 vs 27" PSS-255

Note: the PSS SW spec is adjusted by -.2, because it's on a 8.5" instead of the "measured on" 9".

It has a better sidewall look, without causing any clearance issues.
It's a no-brainer to do this.
Especially with a 305 in the back.
I assure you, it looks much better than the 245 PZero did.

 

Lunar really appreciate the quick feedback. I'll probably just stay with the super sports as they are mounted and ready to roll. The shoulder of the tire is less pronounced and that is what looks like is throwing me off. In your pictures they are clearly wider(305 vs 295) and the heigh of the tire is the same.

How do you like them on your 991 vs the P Zeros? I liked the P zeros on this car for everyday driving and even tracked them a couple of times and they were good. I just like the super sports better from previous experiences with my S5, and 350z.

 

I agree the PZero is a very good tire and there is nothing wrong with them, at all, in dry performance.
I just thought they were a bit loud and rough riding.
They were OEM on my E63 also.

Now that I have the PSS, I think they are nearly as loud and rough riding (so no real gain there).
I like the handling much better though.
It's not a drastic improvement, but the car seems to have more grip and it instills more confidence on turn-in and power-out.
I'm not sure how much of that is due to the PSS or the larger tire sizes.

 

I'm at Porsche. We are gonna throw either 7mm or 15mm spacers in the back and 5mm and see if it helps fill out the fenders. I'll have to live with the shoulder height.