PV=NRT is the only true answer. And since N and R don't change, and V changes little, then P is proportional to T, in Kelvin.
For Kelvin, convert to Celcius, then add 273 degrees.
But you need to know the before and after temps.
Check them COLD before you drive, then simply add X pounds (when you get to the gas station) to those that need it.
Or, overfill, drive home, lower tomorrow.
Accu-tire will calibrate your mechanical gauges. The strain variety are generally more accurate and dont drift as much.
Grant
Grant
gee-lenahan-at-gee-mail-dot-com