Current composition of US fuel.

[Charlie Farley]

Does anyone stateside , know with any certainty , the current biofuel percentage that is added to typical US unleaded fuel ?
I ask as i'm trying to spec seals that are in contact with fuel , for the US
marketplace.
Also, is there any knowledge of this increasing in the coming two or three years ?
Thanks for any help.

 

[Jack]

Andy,
Currently 10% or less Ethanol, expected to increase to 15% within 2 years (my guess). This is in the Southeast USA. May be different in other locations such as California.

 

[Jack]

Ethanol
United States
In the United States, ethanol is sometimes added to gasoline but sold without an indication that it is a component.
In several states, ethanol is added by law to a minimum level which is currently 5.9%. Most fuel pumps display a sticker stating that the fuel may contain up to 10% ethanol, an intentional disparity which allows the minimum level to be raised over time without requiring modification of the literature/labelling. The bill<SUP style="WHITE-SPACE: nowrap" class=Template-Fact title="This claim needs references to reliable sources from April 2010">[citation needed]</SUP> which was being debated at the time the disclosure of the presence of ethanol in the fuel was mandated has recently passed.

This from Wikipedia...

 

[Charlie Farley]

Mol,

Many thanks. Info appreciated.
I pity owners of older cars , with regards to what ethanol is doing to old spec seals. According to my gasket & seal guy , he is also seeing problems with ethanol with regards certain alloys in current engine use.
A couple of years down the line, we may be seeing failures.
But hey , what does the automotive industry care !
After all , no one will sell us a lightbulb that lasts.

 

[Jack]

Older style gaskets, seals and fuel hoses are especially susceptible to degradation because of Ethanol.

 

[Fran Hall RCR]

Viton seals/O rings are the ticket

 

[Kevin Box]

Tanks for new fuels ???

Does anyone know the effects of ethanol on aluminum tanks???
Also the effects on bladder material or ExploSafe?

Is it going to wiser to make tanks from 304 stainless in future ???:stunned:




KevinB

 

[Fran Hall RCR]

ATL now has a bladder material that is designed for all fuels including Ethanol...

 

[Jack]

IMHO, aluminum fuel tanks should be fabricated of at least series 5052 material. This is a marine grade aluminum that is more resistant to corrosion than other series aluminum. The fuel tank should be coated on the exterior with an epoxy paint (best), although I have done mine with Zinc Chromate (sufficient). The problem with ethanol blended gasoline is phase seperation during long term storage. Layers of alcohol, gasoline and water will form, with the water residing at the bottom of the tank causing corrosion. If the car is regularly used, this should not present a problem, however, long term storage may. Use a fuel stabilizer such as Sta-Bil will help. Best to keep the tank either full and use it, or empty and dry (best) for storage. In any case, most aluminum fuel tanks will withstand ethanol fairly well. Another concern that is mostly not thought of, is the Ethanol and water will provide for galvanic corrosion to both the tank and brass or copper fittings to the detrement of the aluminum. Avoid these. Stainless steel or aluminum fittings should cause no problems.

Should you be overly concerned, you can always coat the inside of the tank with an epoxy sealer.

As mentioned in an earlier thread, seals, gaskets and hoses not rated for ethanol will be degraded. Forgot to mention gaskets and seals for sending units!

Remember, this IHMO, but I have designed many, many fuel tanks..