What's In Your Tank?

Is running on pure biodiesel a good idea?


What would be the result if I ran B-100 "100% bean oil" in my trucks? — Reader

There are two different answers to this question, depending on what you mean by "B100 100 percent bean oil." If you mean 100 percent raw vegetable oil that has not been turned into biodiesel, then the outcome would likely be an unhappy one.

The use of raw, unprocessed vegetable oils or animal fats in diesel engines can have significant adverse effects and should not be used. For example, the higher viscosity and chemical composition of unprocessed oils and fats have been shown to cause problems in a number of areas. Those include piston ring sticking; injector, combustion chamber and fuel system deposits; reduced power and fuel economy; and increased exhaust emissions.

This may result in reduced engine life, increased maintenance costs, or catastrophic engine failure. The Engine Manufacturer's Association (EMA) strongly discourages this and points out that it will void the warranty of every major equipment manufacturer.

If, on the other hand, you mean "100 percent biodiesel," the answer is different. Even though it is nontoxic and biodegradable, biodiesel is a fuel that is chemically very similar to diesel.

It is possible to use B100 in a diesel engine, however, there are certain issues to be aware of:

  • B100 is not compatible with some types of hoses and gaskets. Some vehicles, particularly those built prior to 1994, need parts replaced with a more modern material.
  • B100 has performance challenges—particularly in cold temperatures—which have to be carefully managed. Options include using block heaters and keeping vehicles in heated garages. Two additives in development by Innospec and Lubrizol, through funding provided by the National Biodiesel Board (NBB) and Michigan Soybean Promotion Board, have shown significantly better results over existing additives.
  • Most of the Original Equipment Manufacturers (OEMs) strongly discourage the use of B100. Currently, all of the major OEMs recommend up to 5 percent (B5). However, none of them say that using a blend of up to 20 percent (B20) will necessarily void the warranty. Some specifically express support of B20, under certain conditions, such as Cummins, DaimlerChrysler, Case, Caterpillar and New Holland. This is the direct result of years of outreach and research spearheaded by NBB.

As a fleet manager for an Ohio school district, I use B20. It offers many of the same benefits as B100, including reduced emissions and increased lubricity, while moving us down the road towards energy independence. Properly handled, B20 is a drop-in replacement fuel that will work year round in any diesel engine, without engine modification.

No matter what blend of biodiesel you use, one aspect must never be compromised. Biodiesel should be of the highest quality, meeting the national standard ASTM D 6751. Fuel that is even slightly off-spec can cause filter clogging and sediments.

One way to decrease your chances of that happening is to buy fuel from a BQ-9000 Accredited Producer or Certified Marketer. BQ-9000 is the industry's voluntary quality assurance program, which improves fuel testing procedures and reduces the chance of producing or distributing out-of-spec fuel. My fuel is made by Peter Cremer North America, which became the first to complete the BQ-9000 program.

Biodiesel is growing rapidly, nearly tripling production each year. It is simple to use, and no matter what blend you choose, you will be doing something good for the country and the planet.

In my case, I am also doing something good for the health of the children who ride on my district's school buses. By using biodiesel blends, you are doing your part to use a domestically produced fuel, instead of imported oil.

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