I found in the tires the maximal pressure but I understand this is not the ideal. I want to check and mantain the tires on my vehicle with optimal pressure but I can not find the proper figures. A 1997 car, as you can imagine does not retain the sticker in the inside of the driver door, nor in the gas lid.
A useful answer would give me figures in Psi for front and real tires. That's all.

tires are marked with how much air pressure on out side wall

Tire pressures are listed on a chart inside the driver side door.

look on the side of the tire. it tells you