I had to get 1 brand new tire on my 996tt. I had a flat tire on my Passanger side rear tire.

The tires I run are 235/35/19 in the front and 315/25/19 in the rear. I ordered a new Pilot Sport PS2 which was on there before and it has about 3/32 more tread then the other 3 tires which approx. 5 months old (they are 6/32)

I have had it mounted and on the car but have not moved the car. I have an appointment tomorrow to have the tire shaved down to match the other tires which are 6/32 while the new tire is 9/32.

My question is; is it safe to drive about 30 miles 60-70 mph to get to where my appointment is to have it shaved or will it ruin my differential in that short period of a time?

I have heard horror stories with AWD cars and only replacing 1 tire but I am going to have to shaved to match the rest so I am really only worried about the drive to my appointment?

Has anyone else had any experience with this?

Also what PSI do you run in your tires if you share the same size as mine? I have 35 PSI in the front and 40 PSI in the rear.

Thanks in advance for any advice!

 

Subscribed. IMHO, and I don't have experience with this, in hindsight it may have been better to get a rental car and take the tire separately. Curious what others say as well as Porsche's official word.

 

Well I haven't actually driven the car yet with the different size tire on there. I had it towed home and took the wheel off to go and have it mounted and balanced. I just put the wheel on now though.

I had a friend with a Subaru ruin his differential after a month of driving with 1 new tire. Subaru said it may not have been the tire but instead the amount of TQ he had due to aftermarket parts and it just so happened after he installed 1 new tire which may have been a coincidence.

Id rather not chance that though!

 

IIRC Porsche guidelines require both tires on an axle to be replaced if the tread depth percentage is 30% or more between the new tire and the used tire.

 

So does that mean replace both rear tires and have both of them shaved down to match the front 2 tires tread depth? That doesn't make to much sense. Basically the same as matching 1 tire to the remaining 3..?

 

Don't mean to highjack the thread, but I also am running the same tires and sizes, but I am sick of having to get new tires every 5k-8k miles. Does anyone know other manufacturers that make tires that size, but won't mess up our AWD system? I have read all those threads RE: tire ratios etc, but would like real world feedback if anyone has tried anything other than PS2s for those sizes (235/40/19, 315/25/19) thanks

 

With PS2, I was running:

235/35/19 and 315/25/19, No problems for me.


The 40 size inrealtion to rear may be an issue with the AWD cause I think its outside the ratio….

 

Thanks, but it was looking for a tire that is more economical, without messing up my diff. Any suggestions?

 

What power level are you at the wheels?



Hankook RS-3

http://www.tirerack.com/tires/tires....omCompare1=yes

This tire is on a closeout sale at Tirerack. Just picked up 2 for the front.

 

They don't make 315/25/19s. I am running a humble 500hp. Just tune, exhaust , intake.

 

500 Crank……when I asked, I meant wheel.


Regardless you would be fine with any summer tire because you are probably 400-450whp range with awd.

 

http://www.tirerack.com/tires/tires....omCompare1=yes

 

This remains a hotly debated topic with many arguments against even matching tire diameter, as some claim it's a myth. Lots of threads on the topic as well. I, however, am not brave enough to challenge the mainstream, and I do match with 235/35/19 and 315/25/19 PS2's

That said, I would personal not hesitate to drive 30 miles on it for the purpose you state. I refuse to believe our differentials are that sensitive at 3/32nds!

 

My lowly '07 Audi A4 2.0 owners manual specified no more than 3/32 differential side to side. Luckily when I needed a new one it was within spec.

 

you are abslutely fine. 996's dont have LSD's. nothing will get damaged. you can ride like that forever if you wanted.