“…Data are also available for chassis dynamometer tests of CNG-HDD vehicles (Crane and King, 1992;Dunlap et al, 1993;Unnasch et al, 1993;Wang et al, 1993aWang et al, , 1993bFritz andEgbuonu, 1993, Urban Consortium Task Force, 1994). Additional studies of engine dynamometer tests of CNG fuel engines are described in publications by Wallace, 1993a, 1993b;Karim et al, 1993;Swain et al, 1993;Varde et al, 1992. Currently, several ongoing projects could provide more information on in-use emissions of current technology production vehicles. The CleanFleet program has just released low mileage emissions results from nine CNG fuel delivery vans from Ford, Dodge, and Chevrolet with mileages ranging from 4,300 to 11,600.…”