What kind of tire pressure are you guys running? The manual says for 18" wheels (which is what I run), recommended pressure is 36/44 lbs. That seems REALLY high, and ride at that pressure is really rough. I'm on Nitto NT-01s (drive to the track). Hot pressures at the track run about 32/36. But what about cold pressure on the street?

P.S. It's a '99 996 C2

 

I run what the manual recommends for cold pressures on the street. I'm fearful of bending a rim in the northeast.

 

I tend to run about 34/41 at the low end, but never quite at the 36/44 that is recommended.

 

+1. I found this was a lot more comfortable and encouraged better wear, too.

 

Just for clarity's sake, I believe Porsche later put out a TSB changing rear cold pressure to 43 psi.

 

I run 34/40 and I drive alone most of the time.

Also I think the 36/44 is for a car that is fully loaded with passengers and luggage.

 

36/44 on the street. I drop to 42 in the rear for autocross, but I have rear camber close to max at -2 degrees.

Keep in mind I bleed the pressures off between runs to keep the hot pressure the same. I have to pump them back up when I leave the event.

 

I am of the same school as knfeparty. I do pay attention to temps with a contact pyrometer for AX or track days.

 

Same here with 18" wheels. I run the recommended pressures 36/44 psi. But I live in Florida so most roads and flat and smooth. However, I think some degree of consideration has to be given to driving conditions and location, i.e., the track guys adjusting for warm tires, or if I lived in a pothole state, I would experiment adjusting the pressures to obtain a decent ride over bad roads and potholes. Keep in mind those are recommended pressures, a little bit lower to "soften" the tires so the car is not being pounded to death on bad roads is not a bad thing.

 

Remember, more pressure-> less contact patch, less rolling resistance, less rollover onto sidewall when cornering

Less pressure-> more contact patch, more rolling resistance, more rollover onto sidewall

Lowering the pressure might "soften" the effective spring rate of the tire, but you will experience more rolling resistance, more likelihood of a big hit deforming the tire enough to debead or damage the wheel, and more deformation under cornering.

 

right. my main focus on tire pressure is handling not ride comfort. even on the street because that one time you need to avoid a ladder that just fell off a truck is when you will need that razor sharp response from a tire that does not load up deform and then change direction of the car.

 

That's pending results of an investigation by the NFL, isn't it?

 

 

I'm happy with 36/44

 

I have been reading for years to check the 'cold' tire pressure. But what is 'cold' tire pressure? Somewhere it says a minimum of 3 hours after driving. In my garage in upstate NY it is 30 degrees F. right now, but at my condo in Florida it is 80 F. The 'cold' measurement will be dramatically different in each place, as will the tires' performance at the same inflation.

Can't find anywhere that sorts this out technically for me.