What happens when our Strategic oil reserves run out ?

[AZJonnie]

4. The less crude that is available on the world export market, the more consumers and industry pay for energy

In the most general sense, the reserves are typically built up when world oil prices are low, and depleted when world oil prices are high. If the strategic reserve were to become empty, it would be reflective of world oil prices having been high for a protracted period of time. And the longer that condition continues, the less "cushion" there is in terms of being able to protect consumers and industry from large, sudden price shocks.

Put another way, The USA can always "buy more, if it's willing to pay", so the condition of the reserve being empty is not, in and of itself, some particularly important inflection point. OTOH, the reasons it became depleted are reflective of some rather important metrics.