If you have a gasoline engine in your boat and you think you've resolved the ethanol problems that plagued you a few years ago, hold on to your grab-rails: the federal government is considering increasing the amount of the corn-based additive in your fuel.

The move stems from a petition filed March 6 by Growth Energy, the ethanol industry's trade association. The group wants the U.S. Environmental Protection Agency to raise the limit on ethanol content in "blended" gasoline to 15 percent, from 10 percent now.

By law, EPA has until mid-December to rule on the industry's request, and probably won't decide until just before the deadline, lobbyists familiar with EPA procedures say. If EPA does approve the petition, it could take months or years for the change to take effect.

While the agency itself hasn't hinted which way it will go, the Obama administration has been visibly friendlier to environmental interests than was George W. Bush. President Obama repeatedly has praised ethanol's perceived benefits.

An ethanol production plant in South Dakota.The prospect of having to contend with a higher ethanol content in fuel for recreational boats has propelled the boating industry – particularly the Boat Owners Association of the United States (BoatUS) and the National Marine Manufacturers Association – to flank speed.

Both organizations have begun pressing their members to write EPA officials and members of Congress urging them to postpone any action on the Growth Energy petition until scientists have studied the likely impact of raising the ethanol component more fully.

GUMMING UP THE WORKS

Introduction of 10 percent ethanol fuel in 2005 and 2006 wrought havoc with fiberglass fuel tanks and clogged carburetors, fuel filters and fuel-injectors in some boats. Boatyards reported having to rebuild large numbers of gummed-up carburetors.

The presence of ethanol also tends to reduce the octane in gasoline and to separate the water content from the fuel, making the gasoline unusable in many cases. In some instances, it has speeded the corrosion of metal fuel tanks as well as those made of fiberglass.

Ethanol producers say the change is needed to meet standards set by the 2007 Energy Independence and Security Act, which requires refiners to increase their use of biofuels steadily, to 36 billion gallons in 2022. That's up from 11 billion gallons this year.

The effort was still on track in 2008. But the ethanol industry contends that with Americans buying far less gasoline than they did last year, the biofuels target can't be met unless the amount of ethanol in gasoline is increased to 15 percent.

Ethanol producers say they're being squeezed because, while corn prices are relatively high, demand for ethanol has fallen, ethanol prices have collapsed and producers can't make a profit. Several have reported losses in recent quarters, and some have filed for bankruptcy.

To no one's surprise, the ethanol producers' campaign is being bolstered by corn growers, who see the higher limits as a way to expand the market for their crops and raise prices, not only of corn but of other food products that are made from corn or its derivatives.

WILL ETHANOL CAUSE DAMAGE?

The most important concern for boaters is whether increasing the amount of ethanol in gasoline will cause damage to carburetors, hoses, fuel tanks and marine engines, as it did in 2005, when ethanol replaced MTBE, an additive that was scrapped after it was found to be toxic.

The National Marine Manufacturers Association says boat makers have been building vessels for years designed to handle 10 percent ethanol, and that many of the problems experienced a few years ago stemmed from residue from MTBE that the new ethanol pried loose.

A plethora of studies on both sides of the issue show conflicting views on what the actual impact may be. Both sides have been spotlighting the studies that bolster their own arguments.

John McKnight, NMMA's director of environmental and safety compliance, joins other opponents of raising the permissible ethanol content of gasoline in arguing that the results of many of the studies conducted so far are inconclusive, and some are even misleading.

Introduction of 10 percent ethanol fuel in 2005 and 2006 wrought havoc with fiberglass fuel tanks and clogged carburetors, fuel filters and fuel-injectors in some boats.McKnight asserts that even a one-percentage-point increase in the ethanol content of gasoline is likely to hurt marine engines because it would increase the oxygen in combustion chambers and make them burn hotter.

He says the extra ethanol also would dry out rubber parts, such as hoses. It also would pose a problem for boaters who leave gasoline in their fuel tanks over the winter, because the ethanol would separate out the various components of the fuel and leave more water in fuel tanks.

"They need to have more data to support the proposition that this increase isn't going to be a problem – and they don't," he says of the petition's sponsors. NMMA estimates that some 12 million marine engines would be affected by such a change.

Margaret Podlich, BoatUS's vice-president for government affairs, warns that raising the ethanol content of gasoline might negate the warranties on existing marine engines, which were based on the premise that boaters use fuel with only a 10 percent blend.

SUBSIDIES, TAX BREAKS AND QUOTAS

There's also debate over just how much of a pollution-fighter corn-based ethanol is in the first place. Ethanol's opponents, including some environmentalists, argue that producing and distributing ethanol from corn creates more greenhouse gases than gasoline made from crude oil.

It takes 1.5 gallons of ethanol to provide as much energy as a gallon of gasoline, according to the Congressional Budget Office. In 2008 ethanol reduced greenhouse gases in the transportation sector by only 14 million metric tons, or about 0.7 percent of the total, the CBO says.

Earlier this year, economists blamed higher corn prices – brought about partly by the channeling of corn crops into ethanol production – for some 10 to 15 percent of the 5.6 percent surge in food prices between April 2007 and April 2008.

Ethanol production already is one of the most highly subsidized industries in the economy. The CBO says the industry receives 45 cents in tax breaks for each gallon of ethanol that is blended into gasoline. It says producing ethanol wouldn't be profitable without them.

The federal government also protects the industry from foreign competition. Washington imposes a tariff of 54 cents a gallon on imported ethanol, and levies an additional duty of 2.5 percent of the value of foreign-made ethanol.

The American Petroleum Institute estimates that almost three-quarters of the gasoline sold in America last year contained some ethanol. Although the 10 percent blend is by far the most common, EPA has Okayed higher blends for a few late-model cars and trucks.

ANYONE'S GUESS

What the EPA will decide is anyone's guess, BoatUS's Margaret Podlich says. The agency could deny the ethanol industry's petition and leave the blend at 10 percent. Or it could increase the proportion gradually, by raising the cap on ethanol to 12 percent or 13 percent.

Another possibility is to provide for bifurcation, in which the EPA would let refiners manufacture both 10 percent and 15 percent blends during a phase-in period – much as was done when policymakers wanted to introduce unleaded gasoline to automobile owners.

NMMA's John McKnight thinks that would be a mistake – because it would be confusing to consumers and would force gas stations and marinas to maintain two separate fuel tanks to enable customers to choose whichever blend they want.

"Would you require every gas station and marina to put in an extra fuel tank?" he asks.

For now, the ethanol fight is a waiting game, and a lobbying frenzy. The EPA ended its comment period on July 20th – after extending it by 60 days – and is reviewing thousands of entries from lobbyists and ordinary citizens alike.

But there's no doubt that the battle will be hard-fought. The ethanol industry has hired Wesley Clark, the former presidential candidate and retired Army general who once headed the North Atlantic Treaty Organization's military arm, as co-chairman of the campaign and its chief spokesman.

The prospect of having to contend with a higher ethanol content in fuel for recreational boats has propelled the boating industry to flank speed.It also has enlisted the aid of farm-state senators and congressmen, who have been among ethanol's biggest promoters. Opposing them are the boating industry, service-station owners, manufacturers of outdoor power equipment, some automakers and some environmentalists.

The Center for Auto Safety has warned that going to a higher ethanol content in gasoline also could void car warranties that have been issued by major automakers, which generally warn against using a blend with more than 10 percent ethanol content.

COAST GUARD: SAFETY CONCERS

The Coast Guard also has weighed in, warning in a July 2 letter to EPA that the proposal to increase the ethanol content of gasoline "has raised concerns related to a possible reduction in the level of safety for recreational boaters should this [increase] be granted."

The service said deterioration of fuel tanks on older boats as a result of ethanol blending still is "a serious safety consideration," and said the effects of increased ethanol on supposedly ethanol-tolerant components developed for newer boats "have yet to be determined."

"Only after a comprehensive study . . . is complete will sufficient data be available to determine whether or not specific ethanol fuel blends pose an increased risk of injury to the boating public," the letter said.

The battle has just begun to reach the halls of Congress. In June the House Transportation Committee reported out a bill by Rep. James Oberstar (D-Minn.) that would require the Coast Guard to conduct such a study within three years.

And Sen. Susan Collins (R-Maine) is planning to introduce legislation that would delay action on the petition by requiring the EPA to conduct an internal review of ethanol's impact on engines before ruling on whether to raise the cap on the ethanol content of gasoline.

As for EPA, "they're under lots of political pressure," says BoatUS's Podlich. "The ethanol guys are up against the wall. The President likes ethanol, and the new EPA administrator [Lisa Jackson] favors it. I think this is a very big issue for boaters."