We can't really predict when the oil will "run out", but at the current rate of drawdowns on the SPR, plus the overall American oil demand exceeding available supplies (even with demand destruction), we should start seeing major problems start to occur in North-American oil refineries by March-April of next year, as well as a worsening shortage of industrial and automotive lubricants.

This is assuming the war continues past December of this year, and also assuming we can rely on the figures they're giving us for how much is left at the strategic petroleum reserve.