Skip to main content

Does This Stuff Really Work?

When I first came up with the notion of modifying a modern recreational vessel so I could do a side-by-side performance comparison between plain ol’ diesel fuel and the environmentally friendly, vegetable-based stuff getting so much press these days, the idea didn’t seem that complicated. I mean, how tough could it be? All I had to do was find a boat, install a temporary bladder-type tank in her cockpit, cross-connect the tank with the existing fuel system via valves and fuel hoses, and hook up the PMY test gear. Right?

Not quite. When I started playing with the project’s preliminaries several months ago, I quickly struck a big, fat snag.

Oh, I know. Scads of upbeat stories about fuels made from vegetable oils or animal fats are appearing on TV and in newspapers and magazines these days. I’ve read many of them myself. They tout virtues like resource renewability; reduced dependence on foreign oil; speedier biodegradation after spills; increased lubricity for decreased engine wear; increased safety due to lower flash points; and reduced emissions. Additionally, marine-related programs and publications often add stuff about water taxi and other fleet-type operations that are going great guns on either B100 (100 percent biodiesel) or some blend of B100 and regular diesel that offers the above benefits at proportionately diminished levels.

But the marine business is a conservative one, particularly when we’re talkin’ dollars, cents, and warranties. In fact, few if any engine manufacturers today will warrant their products once biodiesel enters the picture, and that’s not likely to change soon, considering the scarcity of solid, field-tested data. So I wasn’t real surprised when a warranty-related problem surfaced just days after I’d begun organizing my wring out. Here’s what happened.

Although Glacier Bay Catamarans, which builds efficient, displacement-type powercats, had valiantly agreed to make a diesel-powered 3470 Ocean Runner available for testing as well as temporarily install an extra fuel system so we could operate on two fuels without contaminating either, the company was worried about warranty, understandably. What if a mechanical problem occurred? What if it proved catastrophic? Who’d pony up $90,000 for two french-fried diesels?


Should you fill 'er up with soybean-based fuel? We test the talk about renevable resources and environmental emissions.

Good questions, of course. And after many phone calls and much corporate-level consultation, Cummins MerCruiser Diesel (CMD), one of Glacier Bay’s suppliers, came up with the answer. “We’re onboard with the project,” affirmed CMD president Scott Patrohay. “The resulting data will be useful to us as well as to your readers.”

Patrohay added that Cummins would cover all potential warranty claims, even catastrophic ones. It would send assistant chief engineer Mike Abraham to the test site on test day to both monitor engine performance and lend a hand. It would gather emissions data on our two test fuels by running them in a test cell at CMD headquarters in Charleston, South Carolina, using an engine that was identical to the two 375-bhp Cummins MerCruiser Diesel QSB380 HOs on our Glacier Bay. And it would blend a so-called B20 mixture (20 percent biodiesel and 80 percent regular diesel) for usage at the PMY test site as well as in the test cell at Charleston. While numerous vessels are presently using B100 with reported success around the world, B20 is currently more quality-controlled and more generally accessible. We deemed it the best sort of biodiesel for a wring out.

This article originally appeared in the October 2006 issue of Power & Motoryacht magazine.