That chart is dated 1989!

Don't you think that in the last 21 years there have been some improvements to tire technology that might render these suggestions just a little bit dated, and suspect?

While I'll grant that the lower pressures on that chart might provide a cushier ride, if the maximum inflation marked on the tire is 120psi I am finding it hard to accept that the tire inflated to that pressure is in any way overinflated.

I'd also bet that you might go a little faster with a little more air in the tire.