Sooting tendency is a laboratory-scale property that indicates how readily a fuel produces soot particles due to its chemical composition . Soot emissions are the second largest source of global warming , and they contribute to ambient fine particulates that cause millions of deaths each year . Alternative fuels can greatly ameliorate these problems given that soot formation depends strongly on fuel composition . Sooting tendency is traditionally measured with the ASTM D1322 smoke point test , which measures the height of a wickburner flame at the point when soot first breaks through the tip. More recently, we have developed an alternative definition based on the soot yield in fueldoped flames, which we call yield sooting index (YSI) . YSI requires orders of magnitude less sample volume than smoke point (100 μL versus 10 mL), which makes it useful for developing new fuel molecules. We have applied it to custom-synthesized alternative fuels such as dioxolanes and polyoxymethylene ethers where the available sample volumes were insufficient to measure smoke point .