BoatUS Special Report


Alcohol & Boat Engines

Is There Another Way?

By Ryck Lydecker
Published: December 2011

Federal law says the nation must increase its "biofuel" capacity dramatically in the next decade, but does it have to be ethanol?

It's zero-dark-hundred at an undisclosed marina somewhere on the western shore of the Chesapeake Bay. Two men noiselessly transfer gear from the covered bed of a pickup truck to the cockpit of the non-descript center-console outboard at dockside. Quickly they stow hoses, canisters, and meters, plus vinyl pouches that sprout tubing with stainless-steel fittings. Two others silently remove unmarked barrels from a storage shed, wheeling them toward the boat.

Finally the men whisk a secret weapon known only as "MPSS" aboard, a white metal cabinet the size of a large ice chest. Laid flat on the cockpit sole, it's below sight from curious eyes that may pass in another boat, or attempt to spy from shore.

Photo of a Mako 19 powered by a conventional two-stroke outboardA verteran Mako 19 powered by a conventional two-stroke outboard,
one of three boats used for isobutanol fuel testing.

Once loaded, two of the team begins rigging the MPSS to its attendant vinyl bag, the hoses tracing umbilicals to the exhaust system of the 175-hp Evinrude E-Tec engine on the transom. It takes more time to rig a battery of sensors — from water temperature and barometric pressure, to fuel flow and boat speed — but eventually and with little fanfare, the boat heads for a quiet creek that shall remain nameless. Once on the unmarked, one-mile-course track, the boat begins a repetitious navigation routine — up and back, up and back — as team members monitor the MPSS, now sucking samples of engine exhaust into the pouch.

This being mid-week, such boring, back-and-forth operation at various speeds apparently goes unnoticed from shore. Two minutes at 5,000 RPM, five more at 4,000 and so on, through a five-stage protocol from wide-open throttle to idle speed in neutral. After several laps, one crewmember switches out the portable fuel tank while another screws tubes from a fresh pouch into the MPSS. The routine repeats, lap after measured lap, until the technical appetites of both pouches are satiated and the boat heads back to the dock.

There, while two men unload equipment and reconfigure the boat to its inconspicuous, every-day appearance, the other two whisk the pouches into the truck. They head south where a late-night rendezvous with a gas-mass spectrometer awaits at an undisclosed lab three hours away. Anticipation in the truck is electric. The secrets the two pouches hold could do no less than revolutionize recreational boating.

Team Biobutanol

All melodrama, intrigue, and clandestine-op allusions aside, the description above is a slightly embellished version of how three marine-industry engineers put together their equipment and expertise in an effort to solve the problem an ethanol increase in gasoline poses for boat-engine manufacturers and boat owners. After a series of on-the-water evaluations and laboratory tests conducted over the summer with, not ethanol, but another alcohol derivative called isobutanol, it turns out they may be on to something.

Photo of Jeff Wasil loading a fresh emissions-trapping pouch Evinrude engineer Jeff Wasil loads a fresh emissions-trapping pouch into the
Marine Portable Sampling System (MPSS) that he designed.

"We know that increasing ethanol content in gasoline to 15 percent wouldn't be good for modern marine engines, which today are designed to run on 10-percent ethanol," reported John McKnight, environmental and safety compliance director for the National Marine Manufacturers Association, who helped organize the on-the-water evaluations. "Ethanol adds oxygen, making engines run hotter, so if they increase the amount to 15 percent in the gasoline, that could lead to mechanical failures." McKnight is referring to the ethanol industry pressing to raise the content to 15 percent, and the partial approval for that given last year by the U.S. Environmental Protection Agency.

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How Bad Can More Ethanol Be?

Gasoline-engine manufacturers and the millions of Americans who use their products have lived with 10-percent ethanol in their automobiles, trucks, boats, generators, and lawn mowers for at least the last decade. Manufacturers and the marketplace have adjusted to the requirement, the public is using it, and air quality is better for it.

Two years ago, ethanol manufacturers began to push for half-again as much ethanol in our gas tanks, which is 15 percent, or what would be called E15. So what could be wrong with 50 percent more ethanol in the gasoline that powers our boats? Plenty, according to a new study conducted by Brunswick Marine and Volvo Penta, which was financed by a $400,000 grant from the U.S. Department of Energy and monitored by the National Renewable Energy Laboratory. For example, a total of 300 hours of E15 running time on three popular models of both 4-stroke and 2-stroke outboard engines (check the website below for specific engines), as compared with running on pure gasoline, showed metal fatigue, misfiring, emissions, and deterioration of some fuel-system components.

The peer-reviewed tests also ran a carbureted 4.3-liter, 4-stroke inboard engine on E15 and it exhibited cold-start problems and increased emissions. For test details, go to


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