A system, in a vehicle consist configured for dual fuel operation and comprising at least one fuel car operably connectable to at least one powered vehicle via a fuel distribution path, includes an energy management processing unit. The energy management processing unit is configured to obtain a first cost of a first fuel, obtain a second cost of a second fuel, and determine a proportional ratio of the first fuel and the second fuel for each of plural power settings available for use during performance of a mission along a route. The energy management processing unit is also configured to determine a trip plan specifying power settings for corresponding plural sections of the route to perform the mission using the first cost, the second cost, and the proportional ratio for the power settings to optimize a total combined cost of fuel used during performance of the mission.