This research investigates traces of generational effects in choice of ethanol as a car fuel. There are evidences that incentive policies applied in the diversification programs of energetic matrix has influenced consumption habits. Despite low consumer involvement in the purchase of commodities, but considering facts such as the oil crisis, the Alcohol Program, the advent of ethanol and flex fuel engines, this study investigates whether there is any effect on the generational preference for ethanol over the gasoline fuel. The study makes use of a survey, applied only to consumers who make decisions in flex fuel cars filling. The sample includes consumer’s wide age range, in order to cover the needs of different possibilities generational effects. The results point to some evidence, particularly for environmental concerns and car involvement.