73-3 Evaluation of the Texaco Stratified Charge (TCP) M-151 Army Vehicle August 1972 Henry L. Gompf Control Device Evaluation Section Environmental Protection Agency ------- Background In testing this spring at the Texaco Laboratories it was indicated that the TCP M-151 vehicle was consistently meeting low emission levels dictated by 1976 Federal emission standards. The following emission values are the average of three tests performed in the Texaco laboratory immediately prior to delivery of the vehicle to EPA. Hydrocarbon 0.28 grams per mile Carbon Monoxide 0.86 grams per mile Oxides of Nitrogen 0.31 grams per mile As part of our cooperative effort with the U.S. Army and to expand on our previous evaluations of the emission character- istics of this vehicle, a confirmatory test program was scheduled in the EPA laboratory. Vehicle Tested The vehicle tested was an Army M-151 1/4-ton truck with a four speed manual transmission. The 141 CID engine was modified to incorporate a stratified charge, multifuel combustion process, In addition, an EGR system using a high and low flow rate valve was installed for oxides of nitrogen control. Three catalytic reactors were employed for oxidation of hydrocarbon and carbon monoxide: a platinum plated swirl reactor, an Englehart PTX platinum catalyst and a Texaco copper chromite reactor. The vehicle was operated on a mixture of Texaco no-lead pump fuel and 2 percent lubricating oil. Test Program The Texaco version of the stratified charge engine M-151 vehicle was tested three times. The test procedure used was that specified for 1975 model year certification. Details of this procedure are described in the July 2, 1971, Federal Register. Due to the presence of lubricating oil in the fuel, additional continuous analyses of hydrocarbon emissions were made using a heated flame ionization detector. Test Results The following table presents the emission data compiled during the EPA evaluation. ------- 1975 FTP Emission Results (all results in grams per mile) Date 5/10/72 5/11/72 5/12/72 HC* 0.40 Q. 33 0.37 CO 0.27 0.12 0.31 co2 566.2 539.1 549.6 NOx 0.30 0.31 0.30 Average 0.37 0.23 551.6 0.30 It should be noted that the TCP vehicle was not capable of meeting the acceleration requirements of the LA4-S4 driving schedule. Conclusions The TCP stratified charge vehicle met the required emission levels for 1976 model light duty vehicles. No estimate of durability can yet be made. * Due to technical operational problems the results of the heated flame ionization detector were inconclusive. Cold FID data are reported. ------- |