In January, 1976, the Office of Mobile Source Air Pollution Control (OMSAPC) of the EPA distributed a report on the results of the sulfuric acid baseline program. The report contained results of tests on 56 non-catalyst and catalyst equipped vehicles designed to meet various light duty vehicle emission standards. Since that time, EPA-OMSAPC has continued testing various prototype vehicles with advanced emission control systems. This report discusses the results of OMSAPC testing since completion of the last baseline program report. Fourteen vehicles were tested for gaseous and sulfate emissions during this period. The objective was to further characterize sulfuric acid emissions from vehicles with technologically advanced emission control systems.