Tire pressure 36f 44r

Tried this according to the book and it made a huge difference in handling. Anyone else use these inflation levels?

What pressures did you have before and what exactly were the huge differences?

that is the OEM tire pressure reccomendation for my C4s. I increase the front to 38 and reduce the rear to 42 to dial in more oversteer.

Drop them to 34f/39r, the factory GT3(mk1) spec., feels much better.

Not that it matters, the factory calls for 32/39 for both Mk1 and Mk2 GT3's. The same for the GT2.

Interesting... what is the optimal pressures on a 996 with 17" rims...? cheers Pete

I don't know about optimal, but factory says 36/36. I usually run similar pressures regardless of tire diameter.

Thanks for the info Viken... I know this has been debated many times... but if I wanted to use tire pressure to dial in more oversteer or understeer how does one do this.... ?

There's some basic guidelines towards the bottom of this page. That's a pretty good start.

ok... thats a good little summary... thanks! Peter

I had 35 in both and recent temp drops in the NE brought them to the high 20's. I should have checked my tire pressure more often. So for a week I was driving on 27lbs of pressure! Warning to people living in the MW or NE , big temperature drops really effect tire pressure.

I am running 34/39 also and find it just right. 36/44 much too much understeer, and a bit skittish.

I run 38/42 on my 18 inch around town and at 42/44 on long trips. Never a problem.

To C4S owners: Do you stick with the 36/44 recommendation? I have been. If you don't what differences do you notice? I would say that my car is quite skittish at times on pavement with some grooves in it. Can this be corrected with different tire pressures, or is it normal. Thanks

no "bumping" on mine at the higher pressure levels, although a firmer ride but more stable at speed.

I use 36/44 on the street, and 32/38 on the track. I drive home from the track with the lower pressures, and can't say that I notice a difference on the street. The C4S does have a tendency to tramline and get skittish due to the sport suspension set up. Once, when had new tires installed, the shop put 32 all around. It seemed smoother on the drive home. I pumped it back up the following day, and it was not as smooth but still smoother than the old. I don't think 32 all around is good for the rears, though.

I religiously ran 36/44 on my car (18s) and found the rears showing wear patterns suggesting they were overinflated. The fronts were perfect..............

I upped my pressure to 36/40 after bending my 18" rims and impact breaking sidewalls on the smallest potholes @ 32/36. The ride is firmer but my C2 handles much better. I know I have some allignment issues however, with the higher pressure I don't wear out the inside edges of the front tires like I used to. The rears are wearing nice and even.

I really am able to tell with a 2lb differential. Any lower and the car feels downright dangerous to me. You can tell it wants more air in the tires at 32lbs. IMHO, the factory wouldn't recommend a specific pressure if they didn't think there was a valid reason for it. I doubt Porsche really cares about tire longevity. I asked Pobst about track tire pressures and fiddling with them and his response is that the factory engineers know best. Edit: For a stock/factory setup which I have.

I agree with you jyoteen. The car wants to wander with too low of pressure. My tires wear evenly at higher pressures. Frankly, I think it is dangerous to have them less than 36/40 cold. As far as wearing...keep an eye on the tread...it will tell you if you need more or less pressure.

I have been experimenting with tire pressure. My car feels really balanced at 34/38. I've tried the fronts from 32-38 and the rears from 34-44. This is on fairly new P-zeros and includes dry/smooth/bumpy/gravel/wet conditions. I don't track the car (until they build the new racetrack due by the end of '05) as of yet.