The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is to increase fuel efficiency in vehicles across every segment of transportation by integrating hybrid hydraulic technology. Hybrid hydraulic vehicles have better fuel economy than traditional vehicles, and so the commercial value proposition is drastic savings on fuel. The initial target market is refuse trucks, because they are heavy and have frequent stops and starts, and therefore waste haulers can see immediate savings in operational costs. Since many municipal trash hauling contracts have integrated fuel surcharges, reduced fuel use will also result in immediate savings to cities and communities. The same hybrid hydraulic design can then be adapted to other vehicle classes, such as delivery vehicles, mail trucks, taxis, semi trucks, and construction equipment. This SBIR Phase I project proposes to develop a fuel-efficient hybrid hydraulic refuse truck. Hybrid hydraulic technology is not yet commercially successful because of 1) the noise/vibration/harshness, and 2) the poor driving characteristics of the vehicle. These problems are caused by the hydraulic motor pump (currently quite noisy) and the transmission plus control strategy (which exacerbate poor vehicle handling). The proposed R&D will use a new motor specifically engineered to be quieter, develop a new transmission to reduce friction, and design a control system to improve driving quality. A newly available ?floating cup? hydraulic motor may finally solve stubborn noise and whining issues, while still maintaining performance and enabling fuel efficiency, but it has never been validated. The R&D plan is to first test the new components, focusing on the floating cup hydraulic motor. Then, modeling of the tested components will confirm the expected efficiency gains on a typical refuse truck collection route. Finally, a tailored control system and detailed design of the mechanical system will validate the driving characteristics and economic value proposition.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.