Professor breaks down temporary OK of E15 fuel
As part of efforts to dampen high gasoline prices, the Biden administration is temporarily allowing gas stations to sell a special fuel blend called E15 year-round. Under the Clean Air Act, E15 cannot be sold in summer because it evaporates more readily in warm weather and can worsen air pollution. Aaron Smith, professor of agricultural economics at the
University of California, Davis, explains how E15 differs from the E10, and the environmental impacts of corn-based ethanol.
Q: What is E1 5 and where is it used? A:
Ethanol has long been a potential alternative to gasoline. More than 93% of the ethanol made in the U.S. comes from corn.
In 2007, Congress passed a law creating a Renewable Fuel Standard, which requires transportation fuels sold in the U.S. each year to contain certain quantities of biofuels. Under this policy, more than 95% of all gasoline sold in the United States is E10 — a blend of 90% gasoline and 10% ethanol. E15 contains 15% ethanol and 85% gasoline. It is available in about 2,300 gas stations in the U.S.
The Environmental Protection Agency has approved E15 for use in any light-duty vehicle of model year 2001 or newer. But, some automakers recommend against using E15.
Q: Why were E1 5 sales barred in the summer? A:
The prohibition on selling E15 in summer stemmed from the EPA’S efforts to reduce smog.
To reduce summer evaporative emissions, the EPA sets seasonal limits for gasoline’s Reid vapor pressure, a measure of its evaporation potential.
Q: Will allowing the use of
E1 5 affect gas prices? A:
No. The Biden administration stated in mid-april that E15 could save drivers 10 cents per gallon on average. That’s hardly enough
to compensate for the fact that ethanol contains less energy than gasoline, so cars running on E15 get fewer miles per gallon than those burning E10.