Surface transportation accounts for a large fraction of greenhouse gas emissions around the world. Vehicles powered by internal combustion engines are becoming increasingly fuel efficient and produce less emissions through a number of technological improvements. One technology category is providing real-time “eco-driving” feedback to drivers, so that they drive more efficiently. Since hard accelerations have a major effect on vehicle fuel consumption and emissions, some eco-driving systems have been developed to provide drivers with feedback through the accelerator pedal in order to mitigate these events. This study evaluates one such system called the Reactive Force Pedal (RFP) that provides different degrees of force feedback to the driver. This study examined two levels of force feedback (LOW and HIGH) that were applied to 40 drivers while driving on a prescribed route in Southern California. Detailed driving data (speed, acceleration, fuel consumption, etc.) were collected for baseline, LOW RFP, and HIGH RFP settings, and subsequently compared. The data were also used to compare different emission models in order to gain insight on future scenario estimation methods. The results show that there is 2% - 3% improvement in fuel economy with the LOW setting, and approximately 3% - 5% improvement with the HIGH setting, when consider positive acceleration events. The technology has different effects among different drivers.