During March 1969, the Coordinating Research Council (CRC) conducted a test program at Pasco, Wash., to investigate a driveability test procedure and the effects of fuel volatility on driveability during cool weather (30-50 F). Fifteen late-model automobiles and eight fuels with different volatility characteristics were evaluated. Driveability was rated subjectively during cold-start and driveaway, and after the car had warmed-up. For the cold phase, driveability was related to fuel volatility as defined by the front-end and mid-boiling range of the fuel distillation curves. However, driveability during the warm phase was not affected by fuel volatility within the range of fuels tested.