Follow the specs written on the sticker on the door jamb. It is a general guideline for tire pressure as determined by Mitsu engineers for the average Gallant with an average load under average use.
The pressure written on the tire is the recommended pressure for the maximum weight that the tire can handle. If you are carrying less than the maximum weight then the ideal pressure will be lower.
For example, the tire sidewall may say something like "MAX LOAD 1500 LBS AT 44 PSI". This means that the tire needs 44 psi to retain the ideal shape and contact patch at that maximum load.
However, your car, with an average load (ie:2 or 3 people plus some luggage) may only place approx. 950 lbs on each tire. Therefore you only need 32 psi to achieve the ideal tire shape and contact patch.
You can take this one step further. If you load your car to the maximum capacity, say 4 or 5 big people plus a trunk-full of luggage for a long trip then its reasonable to put extra air in the tires, to boost the pressure to approx. say 35 to 38 psi. But for normal use, use the sticker's recommendation.