Biodiesel and Engine Warranties

Engine manufacturers set their engine designs and their standards for the fuel to be used in their engines through the lengthy and complicated process required by the American Society of Testing and Materials. For petroleum diesel fuel, the ASTM standard is ASTM D975.

With the emerging popularity of biodiesel used as a fuel in diesel engines, the engine and fuel injection manufacturers encouraged the biodiesel industry to pursue an established and recognized ASTM standard for biodiesel fuel. This new ASTM standard would allow OEM’s and their customers a standard by which to determine how the biodiesel fuel would affect engine and fuel injection system operations compared to the existing ASTM D975 for which engines were originally designed.

The National Biodiesel Board, in conjunction with fuel producers, engine manufacturers and third party verifiable entities, such as government agencies and private consultants, successfully developed a fuel specification standard for B100. This specification was presented to the American Society of Testing and Materials for approval and passed the ASTM’s rigorous standards. In December 2001, the new standard for biodiesel was established and was designated as ASTM D6751.* This standard encompasses B100 (pure biodiesel), for blending with petro-diesel in levels up to 20% by volume.

Engine manufacturers warranty their engines, their materials, and their workmanship – they do not warranty fuel. If there is an engine or fuel injection problem caused by fuel, it is considered the responsibility of the fuel supplier. This is why it is so important that a biodiesel customer purchase their fuel from a reputable fuel supplier who uses a quality feedstock as the basis of their blend.

*ASTM D6751 was updated in 2008 to ASTM D6751-08a