Comparison of Solid Particle Number Emission of Gasoline Direct Injection Vehicles Between CVS and Tailpipe Samplings

In order to investigate the difference of SPN emission from G-DI vehicles, which is caused by sampling locations, ninety-six tests were conducted at three vehicle benches with each two particle counters; the one was deployed at a CVS tunnel in compliance with UNECE Regulation 83 whereas the other was equipped at tailpipe with a pitot-type exhaust flow meter considered as a practice for RDE frontloading developments. As a result, the differences of all tests were within ± 30 %. This was attributed to internal particle processes as well as misalignment of signals between particle number concentration and exhaust flow rate.