A control system and method for improving vehicle fuel economy is provided. A base timing module generates a base timing signal. A trim module generates a timing trim signal based on a calibratable compensation factor. A vehicle speed trim module adjusts a calibration parameter (such as engine timing for example) based on the base timing signal and the timing trim signal. According to some implementations, the trim module includes a base trim module and a vehicle speed compensation module and a calibratable compensation factor module. The vehicle speed compensation module generates a vehicle speed compensation factor. The base trim module generates a base trim signal based on the vehicle speed compensation factor or the calibratable compensation factor. The base trim signal can be based on a speed of the engine. The base trim signal can further be based on a quantity of fuel delivered to the engine.