* A 5 Hp, four-stroke, single-cylinder engine operated in dual-fuel mode was tested, with results indicating that a gas flow rate of 6 liters per minute yields the best brake thermal efficiency (BTE) of 30.7%.
* Optimization experiments with different compression ratios and fuel injector pressures showed that a 240 bar pressure and 23° before top dead center (bTDC) resulted in the highest BTE of 35.1% while significantly reducing emissions of CO and hydrocarbons.