| abstract |
A fuel oil composition for use in a spark ignition engine, which comprises conventional gasoline for spark ignition engine use and a compound selected from the group consisting of an alkynyl alcohol, alkynyl ether, alkynyl ketone, alkenyl aldehyde or an acetal thereof, furan or a furan compound, and an alkenyl ether. The gasoline composition for fuel use renders possible improvement of flame propagation speed over a broad range of fuel/air ratios, easy optimization of the ignition timing of a spark ignition engine, improvement of engine output power independently of operation conditions, improvement of ignitability without using metal components when a spark ignition engine is operated with a lean or rich fuel-air mixture, and reduction of cycle fluctuation caused by the variation in the formation of fuel-air mixture which occurs even at the time of normal operation, thereby repressing fluctuations in indicated mean effective pressure, maximum cylinder pressure and the like independently of changes in the fuel/air ratio. |