Effect of biofuel E85 combustion on fuel consumption in spark-ignition engines.

Biofuels represent an alternative source of energy that should gradually decrease our dependence on crude oil. A rapid development of their use in combustion engines is above all the consequence of their very positive balance of emissions. The possibility of use of biofuels in conventional combustion engines is given by their physico-chemical properties. Bioethanol is one of biofuels that can be used in spark-ignition engines. However, because of its lower heating value, it is necessary to change the mixing ratio fuel/air. The aim of this paper is to evaluate the effect of combustion of a mixture of bioethanol with gasoline (in the ratio 85:15) on fuel consumption in the spark-ignition engine. Experimental measurements were performed using a six-cylinder spark-ignition Peugeot engine with the overall volume of 2.946 cm3, which was equipped with a multi-hole system of indirect injection. Obtained results indicated that the combustion of E85 biofuel markedly increased the reduction of specific fuel consumption (corrected to atmospheric conditions). As compared with gasoline Natural 95, the actual volume consumption of E85 biofuel increased under the maximum engine load in average by 30.4 %. In spite of a relatively high consumption of E85 biofuel the total costs associated with running of a modified engine were lower than those of the engine combusting gasoline Natural 95.