Tire Presure

[hi8ha]

Hi Guys:

My MY99 996 has 225/40Z R18 92Y (Front) and 265/35Z R18 97Y (Rear) Ventus (made by Hankook) tires. The side walls shows a 50 PSI Max on both front and rear tires. The Porsche manual shows 36psi for the front and 44 psi for rear tires. What presure should the front and rear tires have? When should the presure be measured?

[Loren]

Pressure should be measured with the tires cold.

If you are new to Porsche then I suggest stating with the factory air pressures.

To my personal driving style I like how my car handles with 32 front and 36 rear.

Just be careful because you can drastically change the handling.

[deschodt]

I am not sure I am qualified to agree with Loren, but I agree.... 36/44 is a little bouncy and extreme. That said I have bent rear 18" rims probably because the PO went too low on pressure - or whacked a huge bump/pothole, so it's a compromise between protecting your 18" rims and comfort/handling. I run 34-38 now, not that it means anything... I might go a bit lower when the pain from buying new rims subsides...

[hi8ha]

Thanks for you feed back.

Guess witll stick whith what the tires says till I get more used to the car.

[White987S]

You should really:

1) Use Porsche approve tires

2) Set pressures stated in your manual, then make adjustments based on your driving style

[deschodt]

You should really:

1) Use Porsche approve tires

2) Set pressures stated in your manual, then make adjustments based on your driving style

As a side note, more than a direct response, the 44 rear Porsche recommends on 18" wheels seems very very high.

My ex-987 on 18" had a lot lower recommended PSI from the factory. At 44 - probably due to the engine weight over the rear axle - my 996 feels like a cheap motel vibrating bed...

Also, 44 cold turns into 49 freeway and 51 "attack mode"... Those are extreme pressures... Too extreme, I think...

[gota911]

I agree that the OEM recommended 36 F & 44 R is too high. I run 32 F & 38 R, which seems to be a good compromise.

[hi8ha]

Which brands are Porsche recommended tires?

[gota911]

Which brands are Porsche recommended tires?

Porsche recommends tires that are "N" rated, which is a special rating/testing process by Porsche. You do not HAVE to use "N" rated tires, but they are recommended by Porsche. Here is a link to the Tire Rack web site that explains the Porsche "N" rating process.

http://www.tirerack.com/tires/tiretech/tec...e.jsp?techid=26

[toddel68]

You should really:

1) Use Porsche approve tires

Oh please let's discuss this! Or should we rather start the oil discussion? <_<

[cyclocross]

Which brands are Porsche recommended tires?

Porsche recommends tires that are "N" rated, which is a special rating/testing process by Porsche. You do not HAVE to use "N" rated tires, but they are recommended by Porsche. Here is a link to the Tire Rack web site that explains the Porsche "N" rating process.

http://www.tirerack.com/tires/tiretech/tec...e.jsp?techid=26

From the Tirerack link here is the meat of the matter: "...the tire manufacturers may also build other tires featuring the same name, size and speed rating as the N-specification tires for non-Porsche applications. These tires may not be branded with the Porsche N-specification because they do not share the same internal construction and/or tread compound ingredients as the N-specification tires."

After reading about Porsche and tire development in "Excellence Was Expected" I think the N-rated tires are the correct choice.

[iflyjets4u]

Watch out if you use 44 psi for the rears. My '99 996 has Continentals on it and were experiencing rapid center wear with that high of a pressure. 38 psi still seems to show more wear, but like the previous member said, the rims are at risk with much less.

[911dark]

I have 235/35 19" & 305/25 19" on my '99 996 have been using 44 in the rears for the past 6 months. The Pezero Rosso's are showing lots of wear in the middle and inner.

Originally I had the pressure at 38lbs right after having a cross coil-over system installed and out at a track day I just didn't feel like I was getting enough rear rotation so I added the additional pressure. It helped a bunch at the track but between the tire pressure and the coil-overs set at mid compression dampening me and the car have been taking a beating around town.

I'm going to drop back down to 38lbs for the street and see how it goes. Obviously I'll take it easy for a while as I know it can have DRASTIC effects on handling.

[UCrazyKid]

Guess witll stick whith what the tires says till I get more used to the car.

Do not stick with what the TIRE says, stick with what the MANUAL says.

I don't think you can go wrong with the N version of the tires that you car originally came with. Those are likely to be Michelin Pilot Sports or Continentals. Check with your dealer.

The rear tire your car has on it might be a bit small, I think the standard 18" tire is 285 in the rear.

Andy

Edited January 5, 2007 by UCrazyKid

[Cesarfl]

I am running Bridgestone tires RE050 A Pole position , the pressure I run is 32 front and 34 rear, I have a lower suspension by using HR springs, so far wear and ride is much better than higher pressures, I don't know how long they will last bt my last set of Potenza S02 were shot after 15,000 miles, so far I have driven the 050 over 8,000 miles and they look great.

[UCrazyKid]

Cefarl,

I ran S-02's and RE-050s on my S2000. Both are great tires, they seemed to have the same amount of grip. However the RE-050 was much better in the wet and lasted a lot longer for the same treadwear rating of 140. Overall I've been really impressed with Bridgestone tires.

AA

[toddel68]

Do not stick with what the TIRE says, stick with what the MANUAL says.

I don't think you can go wrong with the N version of the tires that you car originally came with. Those are likely to be Michelin Pilot Sports or Continentals. Check with your dealer.

The rear tire your car has on it might be a bit small, I think the standard 18" tire is 285 in the rear.

Andy

I've been running exactly the same Hankook tires for quite a while now (1 1/2years) on my 99C4 and IMHO they perform much better than the original Contis. Same grip, much less noise and less wear.

N-rating might have been a good thing when there were only a few cars out on the streets able to perform as fast as a Porsche. Now there are so many fast and even heavier cars out there that I can see no reason why any other high performance tire shouldn't do the job. They all have the stiffened sidewalls and and high speed stability (not really an issue on public roads in the U.S. :lol: ) Porsche brags about.

BTW: You're wrong about the standard size on this MY being 285.

Thorsten

[UCrazyKid]

BTW: You're wrong about the standard size on this MY being 285.

Thorsten

I was just going by the size on my '02, I guess it changed. My bad.

AA

[Loren]

Just to clarify...

The standard rear tire on MY99-MY01 with 18" wheels was 265. MY02 and newer got 285's.

There is no problem running 285's on the standard wheels. Porsche did that on the GT3 Mk1 and I have been running 285 rears on my MY99 car for over 6 years.

[White987S]

The current Porsche approved (N rated) tires, for the 996, are:

225/40/18:

Bridgestone Potenza S-02 A (N4)

ContiSportContact 2 (N2)

Michelin Pilot Sport Rib (N1)

Pirelli P Z Rosso Asimmetrico (N4)

P Z System Asimmetrico (N3)

Pirelli Winter 240 SnowSport (N3)

265/35/18:

Bridgestone Potenza S-02 A (N3)

P Z System Asimmetrico (N3)

Pirelli Winter 240 SnowSport (N3)

285/30/18:

Bridgestone Potenza S-02 A (N3)

ContiSportContact 2 (N2)

Michelin Pilot Sport Rib (N1)

Pirelli P Z Rosso Asimmetrico (N4)