The National Marine Manufacturers Association released findings from preliminary evaluations of isobutanol-gasoline blends supplied by Gevo, which the association said could be a "promising biofuel alternative to E15."
The tests were conducted by the NMMA and the American Boat and Yacht Council as the recreational boating industry explores alternative biofuels in response to the U.S. introduction of gasoline containing 15 percent ethanol.
The Environmental Protection Agency recently approved E15 for model-year 2001 and newer cars and trucks. However, the marine industry has found that fuel containing more than 10 percent ethanol causes severe damage to boat engines.
Although marine engines are not currently approved by the EPA to use E15, misfueling at the pump is a danger for boaters who are unaware that E15 is not compliant with boat engines.
The NMMA and ABYC isobutanol evaluations tested components, including older fiberglass tanks, and engines during on-the-water testing on inboard, outboard, jet pump and two-stroke outboard engines. The tests showed isobutanol produced no more emissions than pure EPA-approved test gasoline while producing 30 percent more energy than ethanol.
Support from Bombardier Recreational Products and Volvo made the testing possible through the provisions of product, personnel and testing equipment.
What’s more, the U.S. Department of Energy has designated isobutanol a “drop-in biofuel,” meaning it can be used to displace petroleum under the Energy Independence and Security Act of 2007, and increasing its use could help reduce greenhouse-gas emissions.
“We are pleased with the results of the evaluation on isobutanol and look forward to more testing on this and other important alternatives to E15,” NMMA president Thom Dammrich said in a statement. “We know E15 causes significant damage to boat engines, and therefore rushing it to the market is irresponsible and an unnecessary step, especially in light of the promising test results on isobutanol.”