This seems like a silly question to ask, but I am a little confused on what my tire pressure should be at considering I have larger tires. The sticker on the door panel says I should be at 35 psi cold and the tire just says to refer to that, but says something about 40 psi max. My PSI for all my tires is about 42-43 psi and they haven't been adjusted since the tires were put on in June last year by a local shop, so I just assumed they got the PSI correct. So what should my PSI be at for all four tires? Thanks!
Mine are at 45 lbs, but I have 10 ply tires. Your main concern should be full contact of your your tire to the road. Try putting some paint across the tread and drive, slowly, one or two rotations. Look at the paint on the road. Thin paint on the sides, too much pressure. Thin paint in the center, too little pressure
You should test your tire PSI often. The PSI will vary with the air temp and road temperatures. Also if you make long hauls. The tire will heat up if under inflated and possibly damage the plies. Stay below the load rating and PSI maximum rating on your tires.