Fuel and water condensation
I wonder if anyone knows why all fuel (automotive or aviation or otherwise) collects water vapor. For some reason, probably based upon the humidity, water vapor will eventually condense in fuel tanks, and if a vehicle has been sitting for awhile, it may be tanked up, but the car won't start because there's too much water in the gas line.
The typical thing to do is add isopropal alcohol or another alcohol with solvents and this will mix with the alcohol and eliminate it. They make automotive products like Heet and you may have used one before to finally get your vehicle moving.
What if you didn't have it? Well I found a great tip at this link:
[link to preparednessadvice.com
Lot's of good practical advice at that blog in very short articles.
I've recommended purchasing a real chamois before as it's an excellent camp towel since it's so absorbent and so tiny. I've also mention the oft-repeated survival use of collecting dew with it as survival water. It's not a great idea as you're picking up all kinds of contaminant that you can't filter out, but if dehydrated and that's all you have, one is trying to stay alive.
Here, you soak the chamois with pure gas (not what's already inundated with water) and then use the chamois as a filter to remove the water as you pass the contaminated water through it. What pass through should work in a vehicle and the rest is too contaminated to use. It's worth a try in a collapse as you may find gas somewhere that no one else can utilize.
Smart homesteaders at that blog link. It's well worth reading their ideas since they use them every day.