The Environmental Protection Agency (EPA) published in March a notice in the Federal Register with its plan to reduce the amount of sulfur allowed in gasoline, but the notice also included a provision to allow 30-percent ethanol blended gasoline, according to a New York Times report. The proposal has widespread support among fuel technical experts because very high compression engines can run more efficiently using the higher blends of ethanol, according to the Times report. The 30-percent concept is contained in the 938-page text of the proposed Tier 3 rule, which would lower the amount of sulfur in gasoline by two-thirds, to the level required in California. In the proposal, EPA asked automakers and other interested parties to comment on E30.
There is a strong incentive in the EPA proposal. That is, automakers will have the option of having their cars certified to use E30. Before a new car can be sold in the United States, the company must submit data on the vehicle’s pollution output and fuel economy to the EPA. Certifying with E30 would call for engines optimized to take advantage of the blend’s octane rating of 93 or perhaps higher.
Using high-octane premium-grade gas in an engine that does not require it offers no benefit. But, in engines designed to squeeze the fuel-air mixture to very high pressures before igniting it with the spark plug, high-octane fuel burns predictably and can produce more horsepower. Ethanol contains only about two-thirds as much energy as gasoline, gallon for gallon. However, if it is burned in engines designed for high cylinder pressures, it will produce competitive horsepower, the report noted.
Various engine and fuel experts like EPA’s proposal because the EPA is inviting the auto companies to take advantage of the good characteristics of ethanol, including an octane rating that is well over 100. An E30 blend in an engine designed to use that fuel would be attractive to car buyers, with “ridiculous power and good fuel economy,” and owners of those cars would seek out the fuel, unlike owners of flex-fuel cars, a Mercedes-Benz official said.
Experts said that EPA would probably have to do more than just give automakers the option to certify vehicles on E30. EPA would most likely have to mandate its availability to give car shoppers confidence that they would be able to refuel such vehicles, the report concluded.
