The above psi and diameter rule of thumb does not always apply.

For example, to take it to the logical extreme to have proof of concept...

I have a 27" bicycle 1" wide racing tire tire, and a 27" truck tire...i put 30 psi in each, and load on 2,000 lb.

The bike tire contact patch is as flat and wide as its going to get, with a full inch of tread width by about a full inch of tread length, or, about 1 square inch of tread contact.

The truck tire will have perhaps a 8-10" wide patch, and it wil be MORE than 1/8" long...disproving the concept.

If you LOOK at the tread patterns of typical truck tires...and hold them side by side.....the taller tire has a longer tread patch than the shorter tire, and the fatter tire has a fatter tread patch.

Now, when we compare different aspect ratios...the tread change does do the length to width orientation flip shown.