tire psi question, need help on recommended tire PSI
So I replaced the 255/40r19 Pirellis with the 96w rating with Cooper 255/40r19 with the 100W XL tires, the tire shop i think overinflated the tires. one of the tires read 40 PSI. I know my stock tires were recommended at 32 PSI cold. Do you think the Cooper's being XL load range 100W that the correct tire pressure is 40 PSI, or is that too high? I can't get reliable information because the 96W and 100W XL would probably have different PSI recommendations, right ? Then I read, if you under-inflated the tires, they go bad fast, over-inflate them, they get punctures easier. Tires are turning out to be a headache, what is it with every tire shop putting the wrong pressure in every car tire?