This paper presents the findings of the second year of a planned three-year program to investigate the hydrocarbon losses sustained during the refueling of passenger cars. The magnitude and frequency of occurrence of spills by type of spill were estimated from observations of refueling operations during a five-city, four-season field survey. The magnitude of the average observed loss due to spills was 10.6 g and the probability of a spill loss was 0.329. The average spill loss was 3.5 g per refueling operation or 0.3 g/gal of dispensed gasoline. Measurements of displaced hydrocarbon losses were made under controlled conditions during a laboratory study conducted in the Scott all-weather room. A regression analysis of these data yielded a model which estimates the displaced hydrocarbon loss as a function of dispensed fuel temperature, displaced vapor temperature, and the Reid vapor pressure of the fuel. A sample of 732 measurements of dispensed fuel and displaced vapor temperature, taken during daylight hours only, yielded a preliminary estimate of 5 g/gal of dispensed gasoline for the average displaced vapor loss.