[WorkerBee28474]

> Could stepping down from the stored pressure to much lower car pressure cause the icing?

A drop in temperature will be (more or less) proportional to a drop in pressure. See https://en.wikipedia.org/wiki/Ideal_gas_law

[amluto]

Careful, the ideal gas law doesn’t really tell you this at all.

The nice case is adiabatic expansion, and at least the sign of the temperature change has the decency to behave the way one would expect:

https://en.m.wikipedia.org/wiki/Adiabatic_process

The more realistic case for a gas station is Joule-Thomson expansion, and it thoroughly defies basic intuition: https://en.m.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect