I should probably take the time to thank greenhybrid posters for calling this issue to my attention. I finished my worst tank in a year and a half at 42.7 (I used to have a house less than a mile from work, but I recently moved into an apartment across the street from my office. Because of my short, stop and go commute, gas mileage was crappy.) After raising the psi in my tires to 40, I'm back up to maintaining about 49-50, which is about as well as I ever seem to do since I don't do much highway driving.

I am now a "firm" believer in ignoring the 32 psi recommendation in favor of something a bit more robust.