A fuel efficiency engine control system for a vehicle, the system comprising: an input module configured to access a first function corresponding to a user-specified power output of an engine of the vehicle over a time duration; a global positioning system module configured to determine a geographical location of the vehicle; an engine power control module in communication with the input module and the global positioning system module, the engine power control module configured to transmit a second function corresponding to a directive power output of the engine over the time duration for controlling engine power output according to the directive power output of the engine over the time duration; wherein the second function corresponds to an oscillating directive power output of the engine over the time duration based on the global positioning system module detecting a first geographic location of the vehicle, the second function includes a plurality of regions of equal or increased engine power output relative to the user-specified power output of the engine over the time duration and a plurality of regions of decreased engine power output relative to the user-specified power output of the engine over the time duration; wherein the engine is engaged during the plurality of regions of decreased engine power output; wherein the second function corresponds to the user-specified power output of the engine over the time duration based on the global positioning system detecting a second geographic location of the vehicle; and wherein the fuel efficiency engine control system includes an electronic memory configured to store modules and a computer processor configured to execute the modules. an input module configured to access a first function corresponding to a user-specified power output of an engine of the vehicle over a time duration; a global positioning system module configured to determine a geographical location of the vehicle; an engine power control module in communication with the input module and the global positioning system module, the engine power control module configured to transmit a second function corresponding to a directive power output of the engine over the time duration for controlling engine power output according to the directive power output of the engine over the time duration; wherein the second function corresponds to an oscillating directive power output of the engine over the time duration based on the global positioning system module detecting a first geographic location of the vehicle, the second function includes a plurality of regions of equal or increased engine power output relative to the user-specified power output of the engine over the time duration and a plurality of regions of decreased engine power output relative to the user-specified power output of the engine over the time duration; wherein the engine is engaged during the plurality of regions of decreased engine power output; wherein the second function corresponds to the user-specified power output of the engine over the time duration based on the global positioning system detecting a second geographic location of the vehicle; and wherein the fuel efficiency engine control system includes an electronic memory configured to store modules and a computer processor configured to execute the modules.