One recent report from Nature Geoscience will have ethanol advocates convinced that Big Oil's political influence goes far beyond the reach of US borders. That publication, according to Nebraska's Grand Island Independent, says that greater use of ethanol as a light-duty vehicle fuel actually boosts smog levels. That runs counter to many other reports on the subject, though ethanol's environmental prospects have, like everything else related to the subject, been a subject of debate.

The study took a look at what happened when the percentage of Sao Paolo's flex-fuel vehicles that ran specifically on gasoline (instead of the more common ethanol) jumped from 14 percent to 76 percent. The result was that ambient smog levels in the city fell about 20 percent. How that fuel-switching scenario was achieved or measured, we don't know, but there were plenty of vehicles to test, as about 40 percent of Sao Paulo's vehicles can run on either conventional gasoline or ethanol.

The Renewable Fuels Association (RFA) told AutoblogGreen that the Brazil results didn't apply to the US for reasons ranging from the differing emissions requirements to the different types of ethanol blends in Brazil (where sugar cane is used for ethanol instead of corn) to Sao Paulo's local climate.

"We are still examining the study and its supplemental material, but our initial review shows that the authors may have used a questionable methodology. The study didn't measure and characterize actual emissions coming from the tailpipes of vehicles nor the composition of the base gasoline to which the ethanol was added," said RFA CEO Bob Dinneen via email. "As the single most important factor in the formation of ozone will be the relative reactivity of the hydrocarbons coming from gasoline, this itself is a fatal flaw of the study."


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    • 1 Second Ago
  • 3 Comments
      Rotation
      • 7 Months Ago
      I think the RFA is talking out its behind. Ethanol is ethanol, doesn't matter if you use cane, corn or switchgrass to start with.
        Marco Polo
        • 7 Months Ago
        @Rotation
        @ Rotation True, however the environmental devastation created by the practice of producing ethanol from corn in US, is very serious. The US should end the mandate for corn-ethanol immediately, and start examining ways to phase out this environmentally harmful industry.
      Chuck Langer
      • 7 Months Ago
      California gets theirs from Brazil, I wonder how they fit into this. The comical part is the reason they get theirs from Brazil is its cleaner in the creation process. Corn ethanol is actually going to have the same problems with additional green house gases. Corn ethanol threatens our food supply and raise food prices. If this was a coal plant this administration would proudly shut it down. Do they keep preaching climate change and look the other way on this one?