i wouldnt worry too much about running the tires with more air in them. i have been running my tires (sumitomo htr200) at 50 psi for two years. the oem tires had a sidewall rating of 44 (?), but the sumis say 51!

the other night, going home, i went past a sign that said "uneven pavement". usually this means that one lane is lower than the other. not this time! the highway folks had gouged out a section of pavement so they could re-surface it later. they left a 4" sharp-edged cliff at each end of the gouge. by the time i found out it wasnt just a low lane issue i had hit the gouge at about 40 mpg! i had the brakes on as i went into the low area, and let go of them before i hit the far side. WHAM!!! my head hit the roof, my back hurt, and was i pissed!!!

tires and wheels are just fine, thankyouverymuch.

anyway, dont worry about the tire pressure too much. just keep it at or below the sidewall pressure rating. thats what the tire manufacturer says is the max pressure for the tire. the car manufacturer's numbers are a compromise between comfort and mileage, with a bias towards comfort.