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Gasoline Quality Greatly Affects Fuel Systems; Not Ethanol Content

January 29, 2013


EPA's decision to grant the use of E15 in 2001 and newer automobiles and light duty vehicles was based on multiple-year, multiple-aspect testing of more than 88 vehicles.  The testing included evaluations of engines, fuels, lubricants, vehicle performance, durability and emissions.  Each year, EPA receives nearly 500 fuel additive applications, identical to the E15 application, and has approved thousands of applications since the approval program started in 1974.  No fuel additive in history has been studied to the rigorous degree as E15.  More than 67 specific studies have been completed, with another 23 technical documents in support, leading EPA to make a sound decision to allow the use of E15. With our participation and peer review restricted by CRC, we were not involved in this test program.   As a new party to the information, the fact is, it is difficult to glean any game changing information from this new version of the fuel system components report.  In fact, I'm curious why the original report release in December 2011 didn't garner an API press release.  Further, CRC has already studied fuel system-related problems and confirmed sulfur species present in gasoline as fatal toward fuel system components, yet sulfur isn't even mentioned in the report.  It's almost as if the 2009 work that commenced after hundreds or thousands of stranded motorists with empty fuel tanks, and dashboard gauges reading "full," don't exist.  This report should have acknowledged that aggressive test fuels would be highly reactive to fuel system components. Additional questions remain as it is impossible to determine the failing criteria on these fuel system components when regular gasoline was not included in the test matrix. E10 now represents nearly 95 percent of all regular unleaded gasoline. Today's API press release announced the availability of the CRC Advanced Vehicles, Fuels and Lubricants (AVFL) report number 15a. This test program is more of a tale of Jekyll and Hyde.
  • The initial AVFL 15 program (Report Number 662, released December 2011) compared an aggressive E20 (20 percent ethanol / 80 percent gasoline with acids and water added), E10 and gasoline with no ethanol on multiple models of fuel senders, pumps, dampers and complete rigs.  Time and again throughout the report, no negative effects on the fuel systems were deemed significant, except one of the acid laced test fuels, which was expected due to the sulfur poison of the fuel.  The follow up AVFL 15a program (Report Number 664, released January 2013) was restricted to no ethanol, 15 percent and aggressive 15 percent ethanol fuel blends on a severely reduced number of fuel pumps and senders only.  In the figures of the report, specifically Figures 3, 4, 5, the performance loss of these fuel system components was the greatest with either the gasoline with no ethanol or equal to the unannounced, singular E10 inclusion.
  • Several of the models identified in the AVFL 15a study are listed on the National Highway Traffic Safety Administration website for manufacturer recall.  It is unclear how this affects the outcome of the study.
  • The greatest flow loss exhibited was due to exposure to gasoline only.  Figures 3, 4, and 5 of the AVFL 15a (No. 664) report confirm that there is great variability in component selection by vehicle manufacturers; pump type "M" showed the greatest flow loss on the acid and sulfur laced E15 test fuel at 20 percent, while pump type "N" showed the greatest flow loss on gasoline with no ethanol at more than 25 percent and pump type "L" showed a loss of nearly 15 percent also on gasoline with no ethanol.
  • The AVFL-15 project was duplicated by Minnesota State University back in 2008 also using an aggressive E20 test fuel on fuel system components.  Conclusions of the report stated "E20 was found to have a similar effect as E10 and gasoline on fuel pumps and sending units."  This study acknowledged the support of engine manufacturers such as General Motors, Ford, Toyota, Briggs and Stratton.
  • The aggressive test fuel formulation and level of ethanol concentration is highly questionable.  There has been no correlation of real world fuels to the aggressive formula, which dates back to 1993.  Fuel properties have significantly changed in the nearly three decades since this publication.
  • In the same time frame as this CRC project, CRC studied the failure of fuel system components due to poor gasoline quality, which left Florida and Georgia residents stranded on highways. With the completion of that research, a wealth of information has been gained on severe corrosion effects from the sulfur compounds found in gasoline, specifically CRC report "Silver Fuel Level Sensor Corrosion Program." (2009 Report No. 653)  These "global field problems" were finally acknowledged after many years of customer complaints of inaccurate readings of the amount of fuel in the tank.
An interesting final note, the original AVFL 15 program evaluated three fuels with 15 fuel system designs and was classified as a "scoping study" with numerous disclaimers that "...different vehicle designs could have different results" or "...more testing is needed..."  Yet in the follow up program AVFL 15a, three fuels evaluated five possible fuel systems — a reduced number of fuel system candidates — yet there is no disclaimer, or multiple disclaimers, about misinterpreting the results. Lastly, there are several elementary flaws in the report, including an incorrect sulfur detection method used for E15 analysis, lack of corrosion and sulfur reporting for the E15 test fuels, non-standard test methods reported for sulfate and chloride reporting for E15, and a complete omission of the protocol used to determine the pass/fail criteria for the fuel pump testing.  The Minnesota Fuel Pump study clearly states the SAE J1537 Validation Testing of Electric Fuel Pumps for Gasoline Fuel Injection Systems was followed.  Today's events leave me scratching my head with many unanswered questions.