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The current stringent emissions regulations can be achieved by automakers applying different technologies. One of these recent technologies is the downstream lambda sensor to control catalytic converter oxygen storage. This lambda sensor is installed after the catalytic converter and its response is the oxygen concentration of exhaust gases after the converter compared to ambient. This oxygen content is correlated to the amount of oxygen stored inside the catalytic converter. The stored oxygen is significantly important for the emissions conversion trade of between hydrocarbons, carbon monoxides and nitrous oxides. The ideal stored oxygen is particular to each application and engine operational condition. Besides, the flexible fuel applications must be optimized to control the oxygen stored in catalytic converter according to the fuel blend in tank.

Two electrical fuel pumps were performed with different fuels in two different vehicles. The pumps accumulated 60.000 km and 190.000 km in passenger cars. Both vehicles and pumps were designed to operate exclusively with gasohol (E22), one of the pumps was tested with 60% ethanol in volume of gasoline blend (E60) for 60.000 km from June-2001 to February-2004. The other pump was tested with gasohol (E22) for 190.000 km from August 2000 to February-2004. The test conditions represented the actual use of the vehicles. Such test is not common vehicle manufacturers practice application because it requires a considered long period of time for evaluation procedure. This test helps both the analysis of soak time influence and the running time. This paper presents a tribological analysis of the components in order to compare the influence of both fuels on wear mechanisms or other degradation that could be influenced by the non usual E60 fuel.