Law of Amontons for tire pressure

I am a bit confused what tire pressure to use when doing calculations using ideal gas laws such as Amonton’s law (pressure proportional to temperature at constant volume).

As far as I understand a tire pressure of 230 kPa means that the actual pressure is 230 kPa above atmospheric pressure, so is in fact around 330 kPa.

Now if I want to calculate to what value the tire pressure increases if I increase the temperature, should I use 230 kPa or 330 kPa as the starting value for the pressure?

I would have thought that I should use the full 330 kPa since that is the pressure I have, however I see in several places that calculations are done with the excess pressure of 230 kPa. Which is corect?