Tire PSI?

[Hoopy Frood]

You didn't do any damage by lowering the pressure 5 psi, it's just not a good habit to get into. It's possible to lower the pressure when hot and get it too low. As the pressure drops, and the heat builds from the tire flexing excessively, the pressure will increase even more, and you end up in a vicious circle, and it likely won't end well.

[jadatis]

Yes you screwed up, but you also have good quality's. You are a good reader.
And you gave the temperatures.

My long story dissapeared again, an expired token or something,
End conclusion, still usefull to let me calculate the needed cold pressure for you, need tirespecifications and axleweights for it.

[Scott'n'Wendy]

I've got the stock tires on my 381m which require 110psi.

I've got a tire pressure monitoring system so I am always aware of the tire PSI.

During my last trip, it was 100 degrees outside and the tires went up to brushing again 130psi. I wonder how high it will get when the temps get to 115! The tires in the sun were a little bit higher than the ones on the other side of the sun, but overall they were all usually within 123-128psi.

Is that a normal raise in PSI? I know you are supposed to do 110psi cold, but should I lower the cold psi at all when in HOT days?

You're fine. Set them to max psi cold in the morning. And the tires will be fine. No matter how fast you go. No matter the upcoming ambient temps.