AGRICOLA IND 90000167; Paper presented at the 1988 Summer Meeting of the American Society of Agricultural Engineers, December 13-16, 1988, Chicago, IL., St. Joseph, MI: American Society of Agricultural Engineers, 1988. 20 p. (Microfiche Collection fiche no. 88-3020), A farm tractor driver's information system was developed. The system has functions of optimizing fuel efficiency, tractive efficiency and operation costs. The information provided to the driver included optimum transmission gear and throttle position, which if used, would cut the operation costs and/or increase the field capacity. Field test results are presented. (author)