It depends on the tire brand. Check with either Tire Rack or the company that makes your tire. In either case, you are probably looking at around 34-36psi.
My recommended tire pressure sticker is located on the inside face of my glove compartment door. It says 30lbs front and rear. I really don't think you would want to take the tire pressure to the max. rating that's indicated on the sidewall.
I keep mine (though a different size than yours) between 32-34 psi. No problems at all and I get absolutely perfect tire wear. I also check the pressure once a week and possibly more if there are great temperature changes (tires are always dead on).
I changed to 255/45, but that's not much different than stock. You may want to check with the tire manufacuter's website and see if there's any info.