Tire pressure for 100* temperature?

[nautiquelfe]

What tire pressure is everyone running in summer weather? I have pressure 5lbs. below mfg. suggestion, but unsure if this is good enough or not. Also would it be best to fill and check pressure during hot part of day or cool towards the evening? Keep in mind it has been getting near 100* here for some time and the hottest part of the summer is yet to come.

[bigislandboxster]

I BELIEVE you check your tire pressure when the tires are cold.....That is before you drive or just after driving. Can't say what temp is ideal, it always stays between 55- 85 where I'm at.....

[Pablito]

Tire pressure is usually checked on cold tires, mfg recommendantions already factor in the heat build-up difference....However the best indicator is tire wear, middle wear indicates over-inflation, wear on the edges indicates the opposite....Here's a good idea, Costco had introduced Nitrogen mixed air for the tires they sell. The gas helps stabilize the temp inside the tire and aid in a more consistent wear and air pressure, for me it was great news since here in the tropics we have pavement at around 100+ degrees almost all year round....

[limoncello]

For what it's worth - on a hot day at the track in Sc (not to different from AL) my tires started at 36 psi cold, and were 45-50 psi hot after 20 minutes on track. I don't know of any street driving I would do that would get them that hot. You decrease the pressure when that happens - of course when you get home and the tires cool down they are under pressure. pV=mRT. As temp rises so does pressure.
BTW, any info on the Birmingham track? My son works in Huntsville, and I've thought about combining a visit with a track day.

[lexuspilot]

My email from local PCA on Barber Track Day:

The Alabama Region PCA DE track event at the Barber Motorsports Park is just around the corner. It will be here before you know it, so don't delay in getting your registration completed and submitted!
http://ala.pca.org
At our last event, we tested a special Touring class group for Sunday only that was a resounding success. This time we will include the special Touring class group that will run in the regular scheduled groups for both Saturday AND Sunday. Unlike the previous Touring group, this time we will require a helmet for all participants in the group. The group will still be lead by a one or two pace cars, depending on the size of the group.
Of course, all other groups will be assembled based on driver experience and type car.
We look forward to seeing you there. It will be a great weekend.!!

** I apologize if this is a duplicate of previous notificaion that you have already received. I am using two separate email lists that have not yet been merged, so please bear with me.
Thanks, Rick

[Brucelee]

Set to proper inflation when cold. Manual has that data.

Then drive!

[Rail26]

Ah yes, the old "reading the owners manual" trick! Can't Tony Robbins put that on cd or something? Hey, WAIT A MINUTE, I think I'm on to something....what a great idea! For those of us that hate reading and were never hooked on phonics, Porsche should make an audio version of the owners manual! That way I don't have to read and at the same time I will keep from blowing my engine out the back. Hold on, the phone is ringing...yeah, that was MENSA calling...they want their genius back. Gotta go.

[Brucelee]

There is a reason they keep making the manual.

BTW-I tell my customers to keep the manual on the passenger seat for one month. This usually handles the questions.