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ISRN Renewable Energy
Volume 2012 (2012), Article ID 219703, 8 pages
Research Article

Effect of Ethanol Content on Thermal Efficiency of a Spark-Ignition Light-Duty Engine

Istituto Motori, Italian National Research Council, Via Marconi 8, 80125 Naples, Italy

Received 20 April 2012; Accepted 9 August 2012

Academic Editors: M. S. Abdel-Mottaleb and S. Karellas

Copyright © 2012 Luigi De Simio et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The use of bioethanol in the transport sector can contribute to mitigate the greenhouse gas emissions of the vehicles. To achieve this goal, together with a positive energy balance in global productive process of ethanol (well to tank), it is important that adding ethanol to gasoline does not cause a worsening of the efficiency of the internal combustion engine (tank to wheel). In this paper, a research activity on a commercial spark-ignition light-duty engine at the test bench is reported. The aim of the work was to characterize the effect of different bioethanol/gasoline blends on engine behaviour. Blends until 85% of ethanol were tested. Comparative studies of combustion development of gasoline and gasoline/ethanol blends at different concentrations have been made through the analysis of pressure cycles in combustion chamber. Moreover, emissions were collected and analyzed. Emissions downstream of the catalyst, measured with the blends, resulted quite similarly to the gasoline case. Instead, upstream the catalyst a reduction of emissions, proportional to oxygenated content was noted. Moreover, a general carbon dioxide reduction with ethanol blends was achieved due in particular to better engine thermal efficiency.