Tips for biodiesel users

Service agents are the best source of information about your truck’s fuel requirements, but here are some tips I’ve gleaned from experienced biodiesel users and other sources. They should cover blends up to B10.

B100 enthusiasts should check out Biodiesel handling and use guidelines, available from the National Biodiesel Board’s website.

Particle Filters: Most late model diesel vehicles fitted with particle filters cannot use blends containing more than ten percent biodiesel.

Fuel system deposits: Biodiesel can cause deposits in fuel system components including fuel injectors. Some engine manufacturers recommend the use of fuel conditioning additives. Consult the manufacturer's handbook for more information.

Fuel filters: Biodiesel tends to clean fuel tanks and lines. The trouble is that all the crud finishes up on the fuel filter(s). Most biodiesel users change their filter(s) after a few weeks on biodiesel.

Hoses and seals: Caterpillar’s 2009 Fluids Recommendations handbook suggests you keep an eye on hoses, seals, and the like. Well-maintained systems aren’t likely to suffer problems, but as we found out when very low sulphur diesel was introduced last summer, high-mileage nitrile components don’t like changes to their fuel diet.

Tanks and piping: The US Department of Energy's latest guidelines point out that galvanised steel and terne coated sheet metal are not compatible with biodiesel at any blend level. (Terne metal is a tin/lead or zinc/tin coating that makes sheet metal look pretty). Zinc speeds up the oxidation of biodiesel, accelerating crud formation in your fuel. Brass, bronze, tin, and zinc should not be used in biodiesel fuel systems. Come to think of it, galvanised diesel tanks are a bad idea anyway. They make hydrocarbon diesel go rotten big-time.

Service intervals: Manufacturers recommend more frequent servicing for blend percentages above B5. On the other hand, I've seen some apparently reliable reports that engines running on biodiesel need less frequent service intervals. In any case, considering the high capital cost of engines for big rigs and boats, it would pay to use an oil sampling and analysis service such as that offered by Gough's - it costs less than an oil change and it's cheap insurance.

Diesel bug: Biodiesel is less toxic than petrodiesel, and it’s a little more inclined to absorb moisture. Those two factors increase the chance of diesel bug infections.

Calibration: The energy content of biodiesel is about seven percent lower than petrodiesel, but blends up to about B20 tend to burn more efficiently, offsetting much of the power loss. Caterpillar advise against recalibrating the engine to avoid problems when switching back to petrodiesel.

Fuel storage: As with any fuel, the fresher the better. Six months is the National Biodiesel Board’s maximum recommended storage life for biodiesel blends. Locally available biodiesel made from tallow or rapeseed may do better than that. Some oil industry insiders have hinted that they might use stabilising additives to get around this problem. I think that would be a damn good idea - especially for rural users.

Fish and Chips: The exhaust from an engine running on biodiesel smells like fish and chips. If Daryl Hannah's El Camino didn't get you salivating, that exhaust should do it!

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