Fuel Additives: Snake Oil or Good Science?


As one who has spent many hours in exotic locations, cycling bad diesel fuel through a make-shift filtration system, I am as vulnerable as anyone to the promises of a quick and easy solution to fuel problems, which is one reason why Practical Sailor has delved so deeply into this topic.

In 2007, Practical Sailorwarned of the problems related to ethanol-laced fuel (E10), and in 2008, we tested various products claiming to prevent problems related to ethanol and found varying degrees of success. In 2009, we looked at diesel fuel additives formulated to attack biological bugs that thrive in diesel. In the summer of 2012, we looked at gasoline additives, taking a closer look at the standards the industry is using to separate the snake oil from the elixirs. And earlier this year, we published an updatedcompilation of these articles as well as the first report, including our long-term study of fuel additives for storage.



While the ethanol problem has brought a mountain of headaches to boaters, it has ignited a booming trade in fuel additives. Way back in 2012, at the Miami boat show, I heard Gerald Nessenson, then president of ValvTect Petroleum Products (now retired), talk about the state of the finished fuel-additive industry and what established companies such as his are trying to do to fend off what he felt were unsupportable claims by small upstart companies.

Nessenson was quick to point out that the finished gasoline at our pumps already includes a range of additives that deal with issues such as corrosion, fuel oxidation, and deposit build-up. He added that the harsh marine environment presents special challenges and cited the well-documented ethanol-related problems in outboards as evidence that boaters need to be more cognizant of their choices when selecting, storing, and-if necessary-treating their fuel. But when it comes to comparing the fuel treatment products on the market, consumers are effectively left in the dark.

As Nessenson explained in his briefing on the topic: Since there are no industry specifications for a multifunction gasoline additive for finished fuel, just performance tests that were established to meet refinery and engine manufacturer standards, a company can introduce products that do not meet any industry standard for components or testing for performance, long term incompatibility or engine damage that can occur after years of use.

One of the biggest culprits, Nessenson said, was ethanol treatments that comprise alcohol, glycol, or new “space-age” technology claiming superior performance to products that the worlds largest petro-chemical companies develop for the worlds refineries and engine manufacturers; but with no industry acceptable documentation.

The most blatant offenders, said Nessenson, are those companies that claim to be able to restore phase-separate ethanol blends. Phase separation occurs when water in the fuel tank is drawn into the fuel until a saturation point is reached, at which time the ethanol and the water can drop out of suspension into the bottom of the tank. Ethanol-laced gas is more susceptible to this process than non-ethanol blends.

Once phase separation occurs, there is no safe way to treat that fuel, said Nessenson. Engine manufacturers and gasoline refiners state that this is not possible, and if this is attempted, it could cause engine damage.

In our 2009 test, only one product we tested, MDR E-Zorb, claimed to restore separated fuel.

As we continue on with our various studies into fuel additives, PS is interested in hearing about your experiences. We would be particularly interested in hearing about anyone having engine damage attributed to using a fuel additive or a warranty claim rejected on the basis of their using a fuel additive. If you currently use a fuel additive that you know little about, you don’t need to panic.

Such damage typically would not be the result of a single use, but repeated long-term use. Our own testing with both gasoline and diesel treatments indicate that limited use of the most popular brand name products will not cause any harm, but how much good the additives actually do is tougher to measure.

We advise anyone currently using or considering using a fuel additive to first seek the advice of their engine manufacturer. It will be helpful to have some form of NMMA certification standards that make the process of comparing additives easier, but given the nature of this science, I expect we’ll be trying to sniff out snake oil for some time.

Practical Sailor has been independently testing and reporting on sailboats and sailing gear for more than 45 years. Supported entirely by subscribers, Practical Sailor accepts no advertising. Its independent tests are carried out by experienced sailors and marine industry professionals dedicated to providing objective evaluation and reporting about boats, gear, and the skills required to cross oceans. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser who has been director of Belvoir Media Group's marine division since 2005. He holds a U.S. Coast Guard 100-ton Master license, has logged tens of thousands of miles in three oceans, and has skippered everything from pilot boats to day charter cats. His weekly blog Inside Practical Sailor offers an inside look at current research and gear tests at Practical Sailor, while his award-winning column,"Rhumb Lines," tracks boating trends and reflects upon the sailing life. He sails a Sparkman & Stephens-designed Yankee 30 out of St. Petersburg, Florida. Darrell is booking speaking engagements in Colorado, Idaho, California, the Pacific Northwest, and British Colombia this summer. You can reach him by email at practicalsailor@belvoir.com.