Psst, the curb is most likely 6 inches. 6 inches is pretty standard, it's measured from the bottom of the pan on the gutter to the top of the curb. (it's rounded so it's hard to measure it).
Rubber deforms, hit a curb and the sidewall will deform and let the rim hit concrete. Only possible way to avoid it would be if your tires from bottom of tread to rim were greater than 6", my guess would be in some pickups that is true, most likely in any car it would no.