Load Range E tire pressure: how do you keep them up?

carringb wrote:
Normal pressure loss is bout 1 psi per month. Maybe two in the fall as average temps drop. Anything more than that you are probably leaking at the valve stems.

I do not even get that much. I seem to lose about 1 psi per year on all my vehicles. I think the old rule of thumb is no longer valid. Rubber chemistry and tire construction must have improved to the point there is very little air loss anymore.