How Long will a Tank of Fluid Last on the S4?

The Consumption rate depends on the output you are running the machine at.

The Measured times when testing with a 1.3 gallon luid tank were:

Fluid consumption (100%): 300ml/min
Fluid consumption (1%): 25ml/min

This means roughly 15 minutes at 100% output, or blizzard conditions,  and 180 minutes at 1% output, or a soft flurry.