Impact of Fuels and Ambient Conditions on IM240 Emissions 962092
This paper describes an investigation of the impact of various fuels, soak and test conditions on the emissions performance of a MY1996 Corsica TLEV on an IM240 test. The study also probes the impact of turning the engine off just prior to the IM240 test under these conditions.
We found using a Wintertime federal fuel with a sulfur content of 485 ppm that the HC, CO and NOx emissions were increased when compared with similar tests at the same temperature of 16°C using the California Phase 2 fuel with a sulfur content of 32 ppm. When tests using the Wintertime fuel were performed at temperatures lower than 16°C, the emissions increased dramatically.
In control tests, the engine ran at a constant idle for 15 min. prior to the IM240 with no engine turn-off. However, when the engine was turned-off just prior to the IM240, slight increases in tailpipe emissions resulted at 23°C and 16°C using California RFG. Shut-off of the engine using a federal Wintertime fuel, however, resulted in significantly higher tailpipe emissions at 16°C and 9°C. At -7°C, the engine shut-off had little effect on tailpipe IM240 emissions. The individual impacts of fuels, test temperature and engine shut-off can be separated and are discussed in this paper.