Effect of Isobutanol/Gasoline Blends on the Performance and Emissions of an Otto Engine-Powered Vehicle Operating on a Driving Cycle

Abstract

This study experimentally investigates the performance and emissions of a typical vehicle in the Latin American automobile sector—specifically, a 1.6L spark ignition engine with port fuel injection (PFI) was used. The tests were performed using a Mustang MD150 chassis dynamometer under transient running conditions following the worldwide harmonized light test cycle (WLTC). Commercial gasoline (containing 10 vol% ethanol; E10) was blended with 10, 20, and 30 vol% of isobutanol. Results reveal that despite the reduction in the fuel lower heating value (LHV), adding the isobutanol B20 blend can improve the fuel economy by up to 6%. Similarly, when the alcohol content in the blend increased, the carbon monoxide (CO) and hydrocarbon (HC) emissions decreased by 10.5% and 10.2%, respectively. Furthermore, the B30 blend resulted in the lowest emissions but had the highest fuel consumption. Notably, these results were achieved without any adjustments to engine key components. Thus, the effects of isobutanol were consistent with the increase in octane and oxygenation of fuel blends.