I overfill by accident a couple years back and I remember something like the TPMS lighting up but I could be wrong. Anyway I was wondering since you live in CA too, if you run 40psi cold, I am assuming that is cold in the morning around 57-59F? If thats the case, how high does the pressure go in the afternoon around 90-100F?

 

Room temp ish.. around 70 ish. the light hasn't come back since even during warm driving. but i didn't go on the highway again which probably heats it up more due to friction. Could be just a glitch.

 

Cold just means the tires aren't up to operating temp. It's all relative to the ambient temperature. Basically, you should park your car and let it sit for several hours or overnight, and then fill it to the recommended pressure.

 

Running mine at 32 - 33 psi cold.
Hankook RS-4s on oem wheels with oem sizing on the RWD

My tire pressure lights come on at 29psi and don't go away until they get up to 33/34.

 

I keep them at about 34psi cold

 

 

That seems pretty low. If it works for you, by all means, but I agree with most others on the thread that running at the recommended pressure of 36 or 1-2 above that seems to provide a more responsive driving experience. Also you would get better protection of your wheels with more air between the rims and the road. Your low pressure warning light is off, but that doesn't mean you are running at the best pressure for conditions.

For whatever it's worth, I've been running mine at 36, summer or winter, for over two years now and haven't had anything out of the ordinary happen. Sure, I have the dreaded inner tire wear, but no matter what you do outside of modifications, you are going to have that issue.

 

Had i been running any other tire I'd likely be at the 34-36 territory for sure, but I've found that running these specific tires at 34-36 cold, I'd actually lose grip after beating on them and find them above 40psi hot. My friend who runs them same tire on his M3 runs em low at the 32 cold and beats on em from the get go, so I figured i'd follow suit.
I did spend about a month to figure out what worked well for my use case, and i've found that driving hard these tires will gain about 6-8psi from whatever cold was. Pushing past 38psi I'd start losing grip. There is no real science to this, but I'd take the same curving route at the same speed and find which setup i could go faster without losing grip or which would result in me fishtailing.

I obviously wouldn't recommend anyone run this low psi on every tire, but for anybody who runs the same tire as me, you can run them at 32psi cold, as i daily them with 32psi cold

 

2003 SC430 door sticker 33 lbs

 

How do you handle changing temperatures? Do you under or over fill?

 

I maintain a pressures of 35-36 psi on my '16 IS 300 staggered wheel/ tyre setup. The Continental Extreme Contact DWS tyres have a softer sidewall, thus requiring a higher pressure for the steering response I'm accustomed to.

 

I run my tires at 39psi, 41/42 psi when warm. Prolongs the life of the tire