tire pressure
 

Just looking for opinions on what ppl set there tire pressure at. I do some highway driving and alot of around town driving. Right now I have them set at 29/35psi cold. Once warm usually rise to 32-33/38-39psi. Sound about right?

I leave mine at factory settings and monitor the TPMS for correct pressures when cold. All the effort going into changing them for driving other than tracking is not what I want to do. Even if I'm going to do some spirited driving on the back roads, I just leave them as is.

Factory setting for half load - 34/40.

I run mine lower than most at 33/37 cold at 68 degrees ambient temp.

Kurtis,

I tried 29 and 35 because I felt my tires were getting too loud, and I noticed a bit more tire wear. Now I like 33 and 39 (1 psi below 997.1S recommended* partially loaded pressures) as a good balance of noise, handling, and tire wear. I am running Pirelli P-Zeros, 235/25-19 F, 295/30-19 R.

* Correction: For future reference, the 997.1 owner's manual states that the recommended partially loaded pressures are indeed 33 psi Front and 39 psi Rear. The 997.2 owner's manual states that the recommended partially loaded pressures are 34 psi Front and 40 psi Rear. In my case, recommended 997.1 pressures were ideal (not 1 psi below recommended, as I stated above).

So that is the air pressure you fill the tires at when there cold? Thanks everyone for chiming in.

Michelin recommends 36/44 for the PS2 on a 997. 29/35 is definitely underinflated. You would risk wheel damage if you hit any sharp bumps or holes, and wear would be uneven.

Fill with nitrogen to keep pressures more stable.

33/37 cold PSS on c4S. Same tire PSS 29/32 cold on GT3
Depends on tire and car.

Okay cool right on thanks. I'm gonna give that a go and see what I think
33/37 cold

I had read somewhere (here or on rennlist) that gary sims (simsgw) preferred 34/37.

Right on thanks

Michelin most likely recommends 36/44 because that is Porsche's recommendation for full load conditions on the 997. Michelin doesn't want to get sued by some owner because they recommended pressures lower than Porsche's recommended pressure for maximum load, and the guy goes out and has a tire blow out on him.

I agree that 29/35 is under inflated, although I think Porsche has a "comfort" recommended pressure for the 991 of 29/32. How the times have changed. Who would have thought that Porsche would make a 911 with a tire pressure setting of "comfort."

I adjusted mine this morning following the owners manual. For a 2008 C2 with 19 inch wheels and a partial load (usually me by myself), it is 33/39.

I had a similar thread about this very same question, and I found that 33/39 is the best setting for me. I went out and bought a $40 tire pressure gauge, and it makes a difference! There is a huge disparity between the lower quality gauges and the good one. The tpc evens out after some good highway driving, but it reads off when I first start driving and up until I get good highway driving in for a bit. Having it measured even, and cold at that setting gives me great comfort. I'll increase it if I ever have need to increase my weight load, but I can't see why I would.

+1 Same here!

Right on. I put mine to 33/39psi cold. seems to be the general concensus.

33/39 on 20"s are just fine.

34/37 on stock rs spyder cl wheels on my gts

With 10000 mi on my MPSS I have 7/32F and 5/32 rear using 34/37.

Depends on which Carrera. 997.2 cold pressure setting between C2 and C4 cars are not the same. 18" and 19" tires are slightly different cold pressure settings as well for C2 cars. 19" cold pressure setting listed below for "N" spec tires. Always set cold. Hope this helps you.

C4,C4S, Targa4/4S 19" Wheels (Summer or Winter Tires):

Partially Loaded (2 ppl w/o luggage) cold
Front 34 psi, Rear 37psi

Fully Loaded (2ppl w/luggage) cold
Front 37 psi, Rear 44 psi

C2, C2S 19" Wheels (Summer or Winter Tires):

Partially Loaded (2 ppl w/o luggage) cold
Front 34 psi, Rear 40 psi

Fully Loaded (2ppl w/luggage) cold
Front 37 psi, Rear 44 psi

Will any of these tire pressure combos help to reduce the "float" feel from the front end of the 997.2? My tires are 235/35-19 F (36 psi) & 305/30-19 R (42psi).

I run 37 front and 40 rear.

A little float, gonna go down to 35 front and see how it feels.

Thanks for the info, and let us know what you think of 35 in the front.

Went down to 36 front and 38 Rear...

Drove about 100 miles today.

Highway 100mph and above, switching lanes etc...

Mountain roads, Sport Mode haulin glass!

Didn't think once that the pressures were wrong!

Perfect!

I'll try 35 Front tomorrow, leavin the rears at 38.

Be sure to have your bail bondsman's phone number with your. hilarious

Haulin Glass is Legal in Maryland....with K40!

I've got a Big Boyz pen just in case!

I think I'll give 36F and 38R a shot. Post back if you prefer the 35F.

Tried 35, didn't notice diff.

Stayin with 36 front.
Feel more with more.

Thanks for the feedback Eldertec.

Okay so I went and got nitrogen put in my tires. I got them filled to 33 front and 39 rears. When I pulled out of the shop the tps read exactly that. Now because where I live its still cold in the morning ..... -1 degree celcius or lower the tires read as low as 29 front and 36 rears. Should I be doing anything about this?

The 997.1 TPMS is not as accurate as the 997.2 system. Just get a good quality tire pressure gage and keep it in your frunk to monitor what the delta is when tires are cold. A must have for those who track but practical to have anyway

I do know there is a formula of how pressure goes down as the ambient temperature falls but I forget what it is. Recheck what your TPMS says as outside temps get warmer but the car is still cold.

Cold weather will affect your tire pressure
 

If the dashboard indicates low tire pressure and the weather is cold, it's better to ride for a while... More than likely the tire pressure is correct. If the sensors are bad, then just get them changed. Dealers are expensive so a better choice is getting them online. The ones on Ebay or Amazon will work just fine. Else TitanTpms.com cover a large range tire sensors for Porsche. Just be aware of the Radio Frequency.

That advice is contrary to anything I've ever been told.

I agree. If my sensors says my tires are low then I check regardless of the weather. Cold is when you check. If pressure is ok then the TPMS maybe bad.

Agree with jhbrennan and RaidersR1 on this. The warning indicator generally won't indicate low unless the pressure is really low. I would add air if the dash light comes on.

In 997.2 models (not sure about 997.1), the TPMS system actually monitors both the tire pressure and the tire temperature. While the absolute pressure display shows the real pressure of the tire, the delta pressure display (+/- some number) takes the tire temperature, tire pressure, and the tire loading setting that has been entered into account in its report. If you want to observe/adjust pressures based upon your load settings (it also considers summer/winter and 18"/19" tire diameter) regardless of the tire temperature then you can use this display.

One other thought on your suggestion of eBay or Amazon. This forum is loaded with horror stories about many of the non-OEM TPMS sensors being very problematic. Look them up. I went with OEM sensors from one of the Porsche dealers online that discounts them. I thought it was money well-spent not to worry if I was getting compatible ones with good batteries or not... although I have heard a handful of success stories with others well. Mine showed up from with a manufacture date of only two months earlier and worked with nary a problem.

Tire pressure
 

I have mine set at 33/39 (997.2 Turbo) and my TPMS reports -5 under inflated. Comments....can you change the recommended via PCM?