The House of Representatives sided with motorists and consumers when it acted to block the Environmental Protection Agency from implementing a 50 percent increase in the amount of ethanol blended into gasoline.

The House measure requires the EPA to first conduct a study of the broader effects of allowing E15, fuel with a 15-percent ethanol content. Currently, most gasoline sold at service stations has a 10-percent ethanol content.

The EPA had already approved E15 for use in all 2001 and newer light motor vehicles despite numerous complaints the higher ethanol content could cause fuel system damage in cars and trucks and even more serious damage to engines used for ATVs, motorcycles and gas-powered tools such as lawn mowers. Such damage, manufacturers note, would not be covered under warranty, leaving the consumer to foot the bill for repair or replacement.

In addition, ethanol, because of its lower energy content, adds to the cost of refueling. According to the American Automobile Association, today’s nationwide average price for a gallon of E10 (a 10-percent mix of ethanol and gasoline) is $3.497. The cost of a gallon of E85, a mix with 85 percent ethanol is $3.102. However, the miles-per-gallon per BTU cost of E85 needed to equal the gasoline is $4.082, higher than either premium gasoline or diesel fuel. The differential of E10 versus E15 on a cost-per-gallon basis is very small, but over the lifetime of the average vehicle, it becomes fairly significant.

Beyond the higher cost of fuel, ethanol producers have not yet been able to get acceptable yields from waste products like corn husks, meaning that corn is still the primary feedstock for ethanol. The more corn that is diverted from the food supply to ethanol, the greater the impact on a huge range of food products. A government study indicated the switch to ethanol has added 20 percent to the price of some food items. In 2011, the government says more corn went to ethanol production than went to livestock feed.