Joe seen it now tvm, any thoughts on the Continental Winter Tires at Tirerack in 245/45/19 as these apparently just fit and may do the job with my same make rears of 295/30/19 ???

 

I run the 997TT sizes with PS2's

235/35/19
305/30/19

If Michelin sold a 25 profile 305 I would have bought it.

Anyone have problems with this combo?

 

TTDave, the diameter diff you have is 3.1 percent. Good luck,
but I wouldn't do it. If Porsche supplies the for the 997 then
it must be OK though. Richard, I don't know which continental
winter tire you're talking about. I don't even see one in 295/30/19.

 

I looked at the numbers too for them and thought WOW, they are off dramatically.... no good for a 996TT. (817 versus 788 revs per mile) But then I checked and those sizes ARE the 997TT sizes.

Which makes me wonder if the differential is ..different... in the 997. Perhaps the 997 is designed with this rotational difference taken into account!

Anyone know?

A

 

997 awd differential is a different ratio than the 996. You should NOT use 997 tire ratios on the 996

 

997TT has electromagnetically controlled AWD system. 996tt has viscous fluid drive AWD. As stated above, the 996TT AWD system will not tolerate{for long} tires that are out of it's spec range.

Could someone please post the chart they use to compare the proper front and rear tire combinations for the 996TT? I would like to go wider safely.

 

Oh snap...I have the P40 HRE's with the stock 997TT size PS2's. Granted I have not driven at all since the swap due to work, but man...this thread is really alarming. Does any one know what size front PS2 would work with a rear 305 30 19 PS2? I think it would be cheaper to trade out the fronts and keep those nice big meets out back than make the rears narrower etc...anyone?

 

305/30/19 is the problem...

 

+1

If you're running 235/35 fronts, I'd switch the rears to 315/25. Many here, including myself, have run this combo and have been just fine. It sucks to spend the money on new tires, but I believe it's the right thing to do.

 

Closest size I was able to get for 305/30/19 PS2 (26.20 in 665.48 mm) Rears is 225/40/19 PS2 (26.08 in 662.43 mm) and should work with no problems.

 

Thanks for the confirmation- what is OK for the 997 is NOT for the 996.

Just go to tirerack, chose a model of tire and click on "specs"

Here is a link for the PS2:

http://www.tirerack.com/tires/Spec.j...D33YR8SPORTPS2


A

 

I've ordered some 245/35/19s for the front lets hope they fit with my Cargraphic and PSS9 set up

 

Thanks for the info! These are the sizes I will go with for the front!

 

So I did a little research and came up with two combos, that in theory, should work great with using Michelin PS2's and 19' wheels:

1)Ft 22540ZR19 OSD26.1 Revs797
Rear 30530ZR19 OSD26.3 Revs788

2)Ft 22535ZR19 OSD25.2 Revs824
Rear 31525ZR19 OSD25.2 Revs824

Going by the numbers, option number two is mathematically perfect and option one is close. Just thought this might help here...good luck! The info posted here is off of the Tirerack website and cross checked on the Michelin site with very slight variance.

 

I still have not decided after your explanations.

I have a 997 TT wheels.

Can then be mounted to a 996 TT S cabrio?
That should put tires?
That should put spacers?
Affect the mechanics of the car?