they are all rated with a factor of safety in mind. You will see on the sidewall it will say maximum pressure 50psi for example, doesn't mean it will blow up at 51psi, I think tyre pressures have a factor of safety of 2, that means they are perfectly safe at 100 psi!

As for speed ratings, I dont know what the speed rating is, but a tyre rated to 150mph should be perfectly safe for 200mph+.
























Dont quote me on that though