Tire Pressure Change (Cold vs. Warm)…?

I recently installed new Mickey Thompson Baja Boss A/T’s 285/70/17. I started out at 42psi and Incrementally over the course of a couple of weeks and several hundred miles found 35psi to be the sweet spot, or so I thought.

After dropping to 35psi and driving for a solid hour at highway speeds I measured my psi again and all “4” tires had increased to 40psi.

How much can/should tire psi increase (and decrease) from when they’re cold to warmed up and vice-versa?

5psi seems like quite a fluctuation and Discount Tire said I shouldn’t see more than a 3psi adjustment.

Temps in my area have been pretty mild (ie. 50’ish degrees).

Any input is appreciated - thanks!

 

1 - 2 psi for every 10 degrees

 

Costco has a blanket recommendation of inflating +4 PSI over the cold temp when the tires are hot if that helps. (of course YMMV)

Edit: I haven’t paid much attention to the 4Runner but +4 PSI hot was pretty normal on the ol Sorento.