I've been running Goodyear G670 (245/70/19.5) and had to replace this year. FMCA didn't offer the discounts on Goodyear, so I went with Michelin XZE (245/7019.5) With the Goodyears I was running 80psi, but at the Michelin tire shop they set the new tires to 100psi. I'm confused and tried looking up the right psi for the tires. Can anyone help