I have the same scenario as you capri2200 with the factory 20" Goodyear SRA's.... Yep door column says 39, but dealer told me to run them at 41..... Wonder why???
In my old truck with 17's door sticker said to run 40, unless towing then 60 in front and 70 in back.... the latter is the way I ran it most of time because it did get better fuel econ and they wore nicely, I got over 70k on my first set of factory tires by doing that a lot of rotating paired with a balance (every other oil change) ....
ZMan079