California intends to improve its air quality with the introduction of California Phase 2 Reformulated Gasoline (CP2 RFG) into the current fleet of vehicles in 1996. A prior study demonstrated that this fuel change alone can reduce Non-Methane Organic Gas (NMOG) emissions and Reactivity Weighted Emissions (RWE) by 34% and 28%, respectively, relative to the 1990 Auto/Oil Air Quality Improvement Research Program (AQIRP) Industry Average Gasoline (RF-A).1 Beyond CP2 RFG, California plans to progressively reduce vehicular emissions specifications between the years 1993 and 2003, which should force vehicle manufacturers to develop Advanced Technology Vehicles (ATV's) to maintain compliance. This study measured the emissions of 31 ATV's produced by six domestic and foreign vehicle manufacturers. CP2 RFG was found to be just as effective at reducing hydrocarbon mass emissions, Reactivity Weighted Emissions (RWE), and toxics in ATV's as in the current fleet of vehicles. This indicates that the CP2 RFG/ATV's fuel/vehicle system should be an essential element in California's air quality plans over the next decade.