Consider the bicycle tire. The first ten pounds of pressure you put into a completely flat tire do no good at all. And adding ten extra pounds to a full tire will burst the tire, defeating the entire purpose of your effort. No, it’s just the last ten pounds, the ones that get it to full that really pay off. When it’s down five or ten pounds, it might as well be flat. A 10-percent change in pressure makes it defective. If it’s up five or ten pounds, though, the entire wheel is threatened with a blowout. Obviously, it’s the pressure right around full that has the most impact.
