A study was conducted to investigate the effects of commercial E-85 fuel properties on Port Fuel Injector (PFI) durability performance. E-85 corrosivity, not lubricity, was identified as the primary property affecting injector performance.
Relatively high levels of water, chloride and organic acid contamination, detected in commercial E-85 fuels sampled in the U.S. in 2006, were the focus of the study. Analysis results and analytical techniques for determining contaminant levels in and corrosivity of commercial E-85 fuels are discussed.
Studies were conducted with E-85 fuels formulated to represent worst-case field fuels. In addition to contamination with water, chloride and organic acids, fuels with various levels of a typical ethanol corrosion inhibitor were tested in the laboratory to measure the effects on E-85 corrosivity. The effects of these E-85 contaminants on injector durability performance were also evaluated.
Corrosion test ratings from NACE TM0172-2001 (“Determining Corrosive Properties of Cargoes in Petroleum Product Pipelines”) [1] were determined for the test fuels. This corrosion test was found to be sensitive to the presence of low levels of typical corrosive E-85 contaminants. A recommendation for adding a corrosivity requirement to ASTM D 5798 (“Standard Specification for Fuel Ethanol (Ed75 - Ed85) for Automotive Spark-Ignition Engines”) [2] will be presented.