In the paper, fuel economy and emissions of a port-fuel-injection engine fueled with four gasoline were experimentally investigated to verify the validity and universality of the conclusions from the previous experiment conducted in a gasoline-direct-injection engine. On the basis of the previous results, which showed that aromatics and short-chain alkanes were beneficial to improving fuel economy and that oxygenated fuels could reduce emissions to some extent, commercial gasoline with a research number of 92 and three customized gasoline with different aromatic, short-chain alkane, and oxygen contents were chosen to conduct comparative tests in a wide range of working speeds (1000–3600 rpm) without any modification on the engine systems. Results show that aromatics do have great advantages on fuel economy under all operating conditions, while the mean fuel-saving ratio (FSR) of gasoline F with the highest aromatic content could reach 5.25% under stable operating conditions. Moreover, short-chain alkanes ...