Non-ethanol gasoline pump
Ethanol is a beleaguered fuel these days, with national availability E85 nowhere in sight, rollout of E15 seemingly stalled, and concerns over its full carbon footprint hotly debated.
Most drivers pumping gas pay little attention to its ethanol content, which in several states may now be at 10 percent.
Meanwhile, traditionalists seek out pure gasoline for older engines and those in motorboats, lawn equipment, and other offroad uses, which they claim can't withstand even E10.
Ethanol in its purer forms, specifically E85, is long accepted as more corrosive to rubber and other engine components than gasoline.
That's why carmakers have to develop "Flex-Fuel" engines specifically designed to withstand the effects of fuel that contains a majority of ethanol.
But new research appears to show that pure gasoline--known as G100 or E0--is more corrosive to various engine parts than is E10.
Sign for 'ethanol-free premium gas' at Stewart's, Port Ewen, NY, Mar 2015 [photo: William Benson]
At least that's the claim of a post on the website of the Urban Air Initiative, a group that works to promote ethanol use to reduce or eliminate the adverse effects on public health of what are called the aromatic compounds in gasoline.
Published last month, the post alludes to research results presented by ICM Inc. and the institute at a meeting of the ASTM, an international group that develops and publishes standards, including those for vehicle fuels.
According to the post, the research involved "extensive testing done on fuel lines, gas containers, and plastic components" that were bathed in both E0 and E10 fuel for extended periods.
The higher percentage of aromatics in the E0--25.6 percent versus 20.6 percent in E10 gasoline--produced more damage over time to the components than in the E10, it says.
Thus far, we haven't found that study online to look at the full conclusions and test design.
Proposed EPA E15 gasoline pump warning label for ethanol content
A video referred to in the post shows a styrofoam cup melting more quickly in E0 than in E10, in just minutes.
While it's illustrative, it's only minimally relevant to vehicle design; no styrofoam parts are used in powertrains anywhere that they might come into contact with fuel.
The oil industry uses ethanol to raise current gasoline to the minimum octane levels required for sale, a function performed for decades by the now-banned addition of highly toxic ethyl lead.
The EPA does not currently regulate maximum levels of aromatics in gasoline, though it does limit their emission from some industrial sources.
MORE: Flex-Fuel Vehicles And E85: Why Ethanol Isn't Making Its Numbers (Feb 2014)
The EPA website lists the known toxicities and adverse health effects of toluene, benzene, and other compounds.
The Urban Air Institute has as its goal to boost the percentage of ethanol in the fuels mix for U.S. vehicles, to counter adverse health effects of the aromatic compounds in gasoline.
It is partially funded by agricultural business interests.
[hat tip: John Alexander]