It is known that species in the exhaust gas of automobile engines vary\nwith fuel. As such, there is a need to understand the individual\nhydrocarbon (HC) and carbonyl (aldehydes and ketones) emissions from\nmodern engines, especially as the use of alternative and renewable\nbiofuels is set to rise. For gasoline, a promising candidate biofuel is\n2,5-dimethylfuran (DMF). This work presents the key individual HCs that\nhave been identified using gas chromatography mass spectrometry (GC/MS)\nand quantifies the emissions of 13 different carbonyls as specified by\nthe California Air Resources Board (CARB) Method 1004 using high\nperformance liquid chromatography (HPLC). The tests were conducted on a\nsingle cylinder direct-injection spark-ignition (DISI) engine at 1500\nrpm, lambda = 1 and constant ignition timing. For the GC analysis, the\nmidrange HCs were identified using the mass spectra. The results showed\nthat unburned fuel (DMF) dominates the emissions. Other main emissions\ninclude cyclopentadiene, methyl vinyl ketone, 2-methylfuran, and\naromatics. There was no evidence of the emissions of linear alkanes\nexcept methane. DMF produced the lowest overall carbonyl emissions\ncompared with methanol, ethanol, n-butanol, and gasoline and, more\nimportantly, the lowest emissions of formaldehyde.