Not that I necessarily agree with Formula 100% BUT here is a link supporting his argument
Tire Tech Information - Checking Tire Inflation Pressure
We can all agree tirerack is a reasonably reliable source for tire info?
Also, if I have to replace my tires 5k or 10k miles earlier (I have 80k mile tires) but I gain 2mpg over the life of the tires (we'll say 70k for calculating purposes).
Again for arguments sake we'll say I get 30mpg at the car manufacturer spec (35psi) puts me at $10666 in gas for the life of the tire at $4/gallon for the full 80k miles.
Now, assuming I get 32mpg with tires at 44psi but only get 70k miles out of the tires I would end up with $10000 even in gas for 80k miles at 32mpg BUT you have to factor in that I lost 10k miles worth of use on a set of tires, which comes out to 80k/$500 (price of 4 new tires mounted)*10k miles (number of miles wasted on the tire) this comes out to $10062.5 for 80k miles at high pressure.
Now, I understand these calculations are theoretical and actual results may vary but my point is, you have to do the math, if you have a 30k mile tire and over inflating it takes 10k off the life of the tire it's A LOT more significant then taking 10k off the life of an 80k mile hard compound tire. As always I welcome people to point out flaws in my logic, it's just the way I'm doing the math it seems like a 2mpg increase (which isn't unreasonable) would save $500 over the course of 80k miles.
K i'm done!