I know I am gonna piss everyone off here, but the tire pressure recommendation on the side wall of the tire, IS the manufacturers recommendation...THEY put it there. Also, being that it states COLD, it is NOT the MAX pressure as air expands as it heats up, and it is only a recommendation.
Like SEABRONC, and BRONCOHOLIC stated , play with the pressure to find what you like. These are only recommendations.
Also running low tire pressure on the highway increases body roll, which could lead to disaster ie. FORD EXPLORER.