Hmmm, I don´t think the US can derive any measure of immunity from the economic consequences of an Iranian embargo, because they do not import oil from Iran. European and Asian nations do still have enough finances to buy a significant part of the  missing oil from Iran in such a scenario, from other sources like Nigeria etc and this will increase the competition with the US for buying up this oil. There will not be 100% destruction of the demand for the oil that is currently coming from Iran in Europe, Japan, Korea and China. So the US will have to outbid these nations on the remaining oil.
Any discussion of an Iranian embargo should deal with the fact that such an embargo is not a useful "punishment" of Iran as it punishes the enacters of the embargo at least as much. Instead, it might be more useful to discuss it as  preempting the use of the Iranian oil weapon. If the West demonstrates a willingness to absorb the consequences of such an embargo, this is a way of demonstrating to Iran that the conflict is very much "for real" without using military force, with all the possible out of control scenarions resulting from it, right away.