The pressure will be printed on the tires. Don't bother looking for a data plate, it may be wrong. My Volvo plate says 32psi, but the tires I'm running on it are 44psi. Of course, 18 years ago when the car was new, 32 was the norm.

I think the tires they use on school buses are 60psi. Definitely read the tire, it will be on there somewhere.