You make a good point, car manufacturer tire pressure is based on OEM tires as such does it relate to replacement tires. Unfortunately typically if you ask the tire manufacturer they will tell you to go by the car maker recommended pressure, but they do have the data. Suggest going back the the tire installer and asking.

If the current tires are a stock type radial replacement remember they always look low even when properly inflated.

What brand/model of tire are you using, what is the max load rating at 50psi, are these low profile tires or something like the original tire?

 

I have replaced old Pirelli P300 195/70 r14 max 35psi, with Falken 912 205/55 r16 max 51psi. They aren't low profiles, but sidewall size is proportionately smaller than the pirelli.

The tire guy originally had the Falkens inflated at 38psi. But then he checked the recommended pressure on the door sticker, and took it down to 30psi. He said he normally inflates these tires to 38psi - 40psi. But if I wanted to be on the safe side, rule of thumb is to go with the recommended pressure for the vehicle. Which leads back to my issue of the recommended pressure being for stock tires. Also when he had them inflated at 38psi, I saw more of the tread touching the ground, than I do now at 30psi.

 

Try 38psi and see how it goes. The tire installer is just covering himself from any possible liability issues no matter how unlikely. The max pressure on this tire is about 6psi more then the typical stock type. I run at 33-34ish all around on stock tires with no issues or unusual wear patterns. You might experience a rougher ride at higher pressures. Remember the tire is designed to operate at max pressure and still be safe provided the tire load is not over the max amount.

 

So I inflated the Falkens to 39psi, much, much more responsive (it wasn't bad at 30psi). Ride comfort has deminished a bit (doesn't feel as soft), but totally acceptable. My priority was more for handling anyway. I will know about mileage as I drive more.

Thanks for the tips!