Abstract: Unregulated emissions have become an important factor restricting the development of methanol alternative
fuels. Type I emission tests were carried on a chassis dynamometer according to the state standard of China, GB 18352.3-
2005, using a light-duty vehicle fuelled with pure gasoline and gasoline blend with methanol volume fractions of 10% and
20%. High performance liquid chromatography, gas chromatography-mass spectrometry, and Fourier transform infrared
spectrometer (FTIR) were used to measure methanol, formaldehyde, acetaldehyde, acetone, benzene, toluene, xylene and
other unregulated emissions from a vehicle fuelled with different proportions of methanol-gasoline blends. The test results
show that the methods of the integration of FTIR instantaneous values and the chemical analysis of bag sampling can both
accurately measure formaldehyde, benzene, toluene and other unregulated pollutant emissions in the vehicle exhaust. With
increasing methanol content in the fuel, CH4, unburned methanol and formaldehyde emissions increase proportionally, with
the benzene and toluene emissions having a slight increase and acetaldehyde, acetone and xylene emissions remaining
basically the same.

Key words: light-duty vehicle, methanol-gasoline blends, unregulated emissions, measurement methods