1.1 ,This test method provides for the quantitative determination of total olefins in the C4 to C10 range in spark-ignition engine fuels or related hydrocarbon streams, such as naphthas and cracked naphthas. Olefin concentrations in the range from 0.2 ,liquid-volume % or mass % to 5.0 ,liquid-volume % or mass %, or both, can be determined directly on the as-received sample whereas olefins in samples containing higher concentrations are determined after appropriate sample dilution prior to analysis.