This presentation provides information about NREL's real-world evaluations of commercial vehicle technologies, which compare the performance of advanced medium- and heavy-duty fleet vehicles to conventional vehicles. NREL conducts these customized evaluations in partnership with commercial and government fleets across the nation. Current fleet and industry partners include UPS, Workhorse, Parker Hannifin, Proterra, Foothill Transit, Long Beach Transit, BYD, Odyne, Duke Energy, Miami-Dade, TransPower, Eaton, Cummins, Bosch, and Clean Cities/National Clean Fleet Partnership. The presentation focuses on two particular vehicle evaluation projects -- hydraulic hybrid refuse haulers operated by Miami-Dade and electric transit buses operated by Foothill Transit.