Ignition timing sensitivities of oxygenated biofuels compared to gasoline in a direct-injection SI engine

► We examine the ignition sensitivities of DMF and other oxygenated biofuels in a DISI engine. ► We examine the combustion and emissions sensitivity around the optimum spark timing. ► It is found that the order of the sensitivity is: gasoline > butanol > DMF > ethanol > methanol. ► DMF is the only biofuel to produce high exhaust temperatures with high combustion stabilities.