Effect of different functional groups of octane boosters on anti-knocking performance and fuel efficiency

A series of compounds possessing high octane numbers, including alcohols, ethers, benzenes, and cycloalkanes, are used as octane boosters for gasoline. In this paper, the research (RON) and motor (MON) octane number of gasoline fuel with octane boosters were measured using a standard cooperative fuel research (CFR) engine. The brake specific fuel consumption (BSFC) and the combustion process of these blends were measured on an engine bench. The results highlighted the synergistic effect (measured value higher than calculated value) of ethanol in gasoline fuel, with an increase in RON of 3.7 for every 10 vol/% increase, and had low octane sensitivity to gasoline. Cyclopentane had a significant antagonistic effect (measured value lower than calculated value). 1,2-Xylene had the lowest octane sensitivity to gasoline fuel, with an octane sensitivity (OS) of 5.7 at 30 vol/%. The BSFC of ethanol was 2.06% higher than others, but the economic cost was 14.15% lower due to the price. There were limited effects of octane boosters on the combustion, all of which had appropriate content to improve the combustion process. In developing high anti-knocking fuels, a comprehensive decision can be made by considering the effects of octane boosters, combustion, toxicity, price, and cost.