skipro33
Thinks s/he gets paid by the post
Today's gasoline can indeed separate it's alcohol content from the rest of the formula when sitting around and exposed to the air. I prove it every time to folks by putting a bit of gas into a clear glass and letting it sit for 30 minutes, after which, I hold the glass up and look at the bottom. There will be several beads of raw alcohol rolling around the bottom of the glass. Just the little moisture in the air, 25% humidity, has combined with the alcohol and precipitated it out of solution. Add a couple drops of water to a gallon of gas and the whole 10% of alcohol in today's fuel will pull out and sit down there at the bottom of the container.
The good thing is that all cars today are required for their fuel systems to be air tight. You might notice when opening the cap, that there's a hiss as pressure is released. Excess pressure is routed from the tank to the engine for burning through a charcoal canister as part of the emissions system. SMOG checks test the cap for it's ability to still hold it's seal and so is the tank. At least here in California they are. Fuel stabilizer additives help emulsify fuel so the gas and alcohol won't separate.
As for the reason there's alcohol in gas to begin with, it isn't a hydro carbon so it doesn't produce the pollution fossil fuels do. One way to 'cheat' a smog test is to run the fuel down very low, last 2 or 3 gallons, then pour in some HEET from the auto parts store. Yellow label, the red label isn't the same stuff, maybe 3 or 4 bottles worth. The emissions will read much lower during test than straight up gasoline. Not that I"VE ever done that, but older cars having trouble to pass SMOG have figured this out. Maybe that's why HEET is still sold; there's a market for it.
The good thing is that all cars today are required for their fuel systems to be air tight. You might notice when opening the cap, that there's a hiss as pressure is released. Excess pressure is routed from the tank to the engine for burning through a charcoal canister as part of the emissions system. SMOG checks test the cap for it's ability to still hold it's seal and so is the tank. At least here in California they are. Fuel stabilizer additives help emulsify fuel so the gas and alcohol won't separate.
As for the reason there's alcohol in gas to begin with, it isn't a hydro carbon so it doesn't produce the pollution fossil fuels do. One way to 'cheat' a smog test is to run the fuel down very low, last 2 or 3 gallons, then pour in some HEET from the auto parts store. Yellow label, the red label isn't the same stuff, maybe 3 or 4 bottles worth. The emissions will read much lower during test than straight up gasoline. Not that I"VE ever done that, but older cars having trouble to pass SMOG have figured this out. Maybe that's why HEET is still sold; there's a market for it.
