With the passage of the Energy Independence and Security Act of 2007 (EISA), Congress doubled the corn-based ethanol mandate despite mounting questions surrounding ethanol’s compatibility with existing engines, its transportation and infrastructure needs, its economic sustainability, and numerous other issues.

Then as now, I believe it is just too early to significantly increase this mandate — the fuels industry needs more time to adapt and catch up with the many developing challenges facing corn-based ethanol.

{mosads}The most pressing issue facing corn-based ethanol is the so-called “blend wall” of 15 percent. EISA mandated 15 billion gallons of corn-based ethanol by 2015. Here’s the problem: Federal regulations require that a gallon of gasoline should contain no more than 10 percent ethanol. So there’s more ethanol production than the amount of ethanol allowed in gasoline.

So what is the solution? Ethanol advocates have the wrong approach. Rather than rethink EISA’s mandates, they are lobbying for higher, mid-level ethanol blends in gasoline. Sounds like a simple solution, except its consequences would be dire, with potential damage to agriculture, the environment, and engine equipment manufacturers.

Most on-road and non-road engines, vehicles, and equipment are not designed to run on ethanol blends higher than E10. The available evidence indicates that lawnmowers, chainsaws, snowmobiles, recreational boats, motorcycles, and non-flex-fuel cars and trucks produce higher evaporative and engine exhaust emissions using mid-level ethanol blends. Also, mid-level ethanol blends are more corrosive on certain metals and plastics used in many fuel systems, and cause many gasoline-powered engines to run hotter and at higher RPM levels. In turn, this results in adverse impacts on starting, durability, operation, performance, and operator safety, due to the degradation of critical components and safety devices.

The public comment period for the ethanol industry’s petition for a Clean Air Act waiver to increase ethanol blends to 15 percent came to a close on June 20. A myriad of groups submitted comments in opposition to the waiver.

For example, the National Cattlemen’s Beef Association, stated, “Cattle producers support energy independence and the development of the renewable fuels industry.” They continued, “What we don’t support are government mandates that disrupt the market and favor one industry at the expense of others. All we’re asking for is a level playing field.”

The Association of International Automobile Manufacturers concluded, “The consequence of potential equipment malfunctions caused by the use of E15 extends beyond failure to sufficiently control emissions. It will also create a high risk of consumer dissatisfaction due to drivability problems which would needlessly damage product reputation and imperil customer satisfaction with dealer service.”

The Alliance for a Safe Alternative Fuels Environment pointed out the potential for consumer confusion: “AllSAFE has strongly cautioned the EPA against such a measure since consumers could be confused and possibly use the wrong fuel, especially if they see that E-15 is cheaper and choose that blend rate to save money.”

Few could dispute that Congress erred in pushing too much ethanol too fast. In this light, EPA must reject calls to issue a waiver until more data is available.

Despite the drawbacks of today’s corn-based ethanol mandates, I do support a role for ethanol and other biofuels in lessening our dependence on foreign oil. Also, I support research into cellulosic, algae, landfill waste, and other biofuel options.

America’s energy supply should be clean, diverse, abundant, and affordable. I believe we must utilize all domestic energy resources, including ethanol and advanced biofuels. Yet our policy on biofuels must be balanced and workable, so as to provide energy security and environmental benefits for consumers.

Inhofe is the ranking member of the Senate Environment and Public Works Committee.