E15 Proposal Faces Skepticism from Experts
Former Iowa Senate majority leader Mike Gronstal recently advised California Gov. Gavin Newsom to increase ethanol content in gasoline from 10% to 15%, known as E15, to lower fuel costs and boost his profile in Iowa as a potential presidential candidate.
The proposal may seem appealing, but experts argue that the actual situation for E15 is more complicated than Gronstal suggests. A June analysis by S&P Global found that U.S. corn yields have increased faster than market demand, resulting in an overabundance of corn and downward pressure on prices.
Economist Aaron Smith's 2025 analysis of potential E15 sales and pricing in California also casts doubt on the proposal. He found that even widespread adoption would have only a limited effect on prices due to consumer wariness and gas stations' reluctance to install new pumps and labeling.