Gas...and a moldy gas hole. :)

[Woodstramp]

"The fuel contains up to 10% Ethanol"

I see this more and more these days. You can hardly find a fuel station that doesn't have ethanol. I pay attention because most of my cars are old.

One thing I've also noticed on all three of my vehicles is a dark mold that grows only in the gas cap hatch. This stuff is tough to clean, too. Also, I've never noticed this in the past. The fill area has been dirty, but not moldy. I wonder if this is associated with the increase of Ethanol in gasoliine. This is the only thing I can figure. Anyone else notice this?

[Ageless]

If it's been damp (like we have in the PNW) that crud just needs a speck of dirt to start growing. As any alcohol will sterilize; doubt that ethanol is gonna feed anything.

[Miriam C.]

Ethanol will break down certain rubber type stuff. Some cars can't use it because they have plastic/rubber parts where gas gets. Makes a fire hazard. Possibly this is happening on your gas cap. Kinda like an old sink stopper will get soft and yucky.

[caseydog]

Ethanol in gasoline is an oxygenator, required in big cities and their suburbs, like where I live. It is not required in low population density areas where ozone levels are low.

I was in rural Oklahoma on Monday, and the pump gas I bought didn't have ethanol in it. So, why would pump gas in rural Wyoming have ethanol in it -- especially in a cold weather month, when an oxygenator is not really needed.

And, Slowcowboy, it is not "half ethanol." It is either 10 percent or 85 percent, and the 85 percent stuff is labeled E85, and won't run in vehicles not certified for E85 fuel.

Gasoline that is oxygenated with ethanol can decrease fuel economy, but not in half.

I am not a fan of ethanol for running cars, but I at least have a realistic opinion of the pros and cons of ethanol. Ethanol is, at best, a stop-gap measure. At least the corn based ethanol we use today.

However, we will NEVER have a sound energy policy in America if we keep believing hyperbole, and ignore real, rational science.

CD

[caseydog]

Ethanol will break down certain rubber type stuff. Some cars can't use it because they have plastic/rubber parts where gas gets. Makes a fire hazard. Possibly this is happening on your gas cap. Kinda like an old sink stopper will get soft and yucky.

Any alcohol can draw moisture, that can condense and form mold.

All gasoline in Dallas has ethanol in it, since MTBE was banned. I have NEVER seen or heard of mold on a gas cap on a car fueled with 10-percent ethanol gasoline. That doesn't mean it can't happen. In cold areas, there is a higher chance of humidity condensing as a car goes from operating temperature, to nighttime temperatures, so maybe mold can form. Since it doesn't happen to me, I haven't looked into it. I honestly don't know.

But, the internet is amazing. Twenty minutes with Google could explain the whole gas cap mold thing.

Or, people can find hundreds of explanations to meet their pre-conceived notions.

CD

[Woodstramp]

I just guessed that ethanol might be the cause of this because I've only seen it since ethanol became so common. Of all the cars I've owed since the late 70's I can't recall one with dark mold growing in the gas fill well. One car (I don't wash very often) is almost black with mold.

[madjack]

...in our area, almost all the gas is 10% ethanol in the warmer months(even in winter this year)...I have noted a 2mpg decrease in my 20mpg vehicle with this type of gas ... hmmmmmmm, a 10% decrease in economy with 10% ethanol gas...it must be a vast conspiracy by nefarious forces .........
madjack