I have a 2017 Carrera with 20 inch wheels. tire pressure is set to recommended comfort settings. Today was 100 degrees outside and the rear pressure reached 51 psi and fronts were 41-42 psi, is this normal or should let some air out if this happens again?


thanks

 

If you set your pressures correctly when the tires are truly cold you're good to go. Just sitting in the sun they'll rise considerably, and as your drive too. What are your cold pressures? 40s and 50s seem high though. Makes me think you're starting too high to begin with.

 

I run 20" wheels on my 4S. My cold temp settings are 31 front and 35 rear. Could go to 34 rear. Check where you are starting cold temp is you are possibly high.

 

Check your starting temps. How long since you checked them? I've seen 10lb difference based on outside temps when cold

 

I checked them and they were too high when sent from dealer. Corrected to 34 front and 44 rear and now much better.

 

You should reset them to a 3-4 lb difference front to rear.


Dealers typically set the pressures to the factory recommended "fully loaded autobahn speed" settings. One presumes that is the "anti-liability" setting.


Those are way too high for normal use on US roads. If you set the cold pressure to around 32 front and 35 rear, it may grow when hot by up to about 5 lbs in each tire depending on the ambient temperature and in normal driving, and still be reasonable comfortable.


PS optimal handling is with the lower pressures: if tracking the car lower to that range whenever possible.

 

Obviously you can run whatever tire pressure you want. I have 305's on the rear of my 4S and my rear cold pressures are 35. Unless you drive the car with 4 passengers, loaded frunk and you personally are over 300 pounds then 44 is too high. Try the lower pressures and see if you notice a better ride and feel.

 

Set them cold. I wouldn't worry about their hot pressure as the tires and settings are all based on cold. I find the normal recommended pressures to be a bit harsh on choppy streets in my area, .. I do 35 front.. and 40 rear..

 

I even find that harsh
2013 4S
20"
33 front
35 rear

 

Same here 2013 4S 20" MPSS 32 front 35 rear. Car handles and rides great

 

I just drove today from AZ to Northern CA and my fronts are 32 and rears are 36. Temps were as high as 114 and as low as 73 on the drive and my pressure showed 33 in the fronts and no change in the rears. Nitrogen in tires. I've had the Porsche 6 months and have never seen a change in pressure when checked cold. 2017 991.2 C4 20" tires.

 

I run about 33 psi front/39-41 psi rear on cold.