[rs19cew]

I found out over-inflating your tires, will result in loose steering issues. This issue was not even discovered by the dealership. They thought it was because Sport mode has a bumpier ride. So make sure the tire pressure is about 33psi on every tire for the best ride, not higher than 35.

[enzia35]

Look at the door jamb for proper PSI on stock tires.

[WhiteMale]

Originally Posted by enzia35

Look at the door jamb for proper PSI on stock tires.

This is the correct answer.

[17rsvert]

Originally Posted by rs19cew

I found out over-inflating your tires, will result in loose steering issues. This issue was not even discovered by the dealership. They thought it was because Sport mode has a bumpier ride. So make sure the tire pressure is about 33psi on every tire for the best ride, not higher than 35.

Unless the spec changed, the recommended cold pressure is 35 PSI for my 2017 RS. I never have a problem with a harsh ride, even though the tires sometimes get up to 38 or 39 after warming up. How high was the pressure when you had steering issues?

[ctrlz]

Originally Posted by 17rsvert

Unless the spec changed, the recommended cold pressure is 35 PSI for my 2017 RS. I never have a problem with a harsh ride, even though the tires sometimes get up to 38 or 39 after warming up. How high was the pressure when you had steering issues?

Agree, I think there might be something else going on with the steering.

Since "cold" right now is the high 70's in my garage, on my morning commute I typically start at 34-35 and 15 minutes later pressure is 36-37 when I get to work. On a hot day in the 90's, pressure may be 37 when I leave and 39 by the time I get home. This never noticeably affects my steering.

[enzia35]

If you have changed the tires to one with a different load rating, use this calculator:
https://tiresize.com/pressure-calculator/

[rs19cew]

37PSI and the ride was loose and jiggly, but stable.

[matt fe2o3]

I think this has all the makings of an oil thread. Every tire is different and there are some variables on inflation based on the tire itself.

On my 2SS I ran two sets of wheels/tires. The F1 Run-flats and the PS AS3's. At 33 PSI (cold) on the F1s the tires were planted and stable. On the PS3's the sweet spot was 37 PSI cold.

You figure this out quickly but it takes a couple days. Cold is ambient temp of 60 degrees IMHO - but it might be 70 degrees if you are in San Diego.

Start on Monday at 33 cold. On Tuesday go to 37 cold. One Wednesday try 35 cold. Each day do the same trip/commute. You will find the right spot for the specific tires you run.

33 PSI on the PS3's was murder. 37 PSI noticeable transformation.

Super simple stuff but don't try to guess - get out and try. Even a variation of the same tire from one year to another of MFG can make a difference. The wear of a tire can as well. Have fun with it.