Iso heet is methanol. It has one job it does well keep water from freezing in fuel line and tank. It does little if any thing after it freezes.
Iso heet goes to the bottom of the tank it mixes with standing water it does not take water that is suspend in fuel out.
It will not reduce gum or varnish nor stabilize fuel.
They do not even make that claim.
It will not hurt anything as long as you do not over do it. But it is not a replacement for fuel treatments or stabil.
It does the same thing in diesel fuel.
