Study of the impacts of engine oil on gasoline particulate filter performance through a real-world fleet test 2019-01-0299
Stringent emission legislations with real driving emissions (RDE) requirements are being introduced in the form of the Euro 6 and China 6 regulations. Particulate number (PN) control requirements are included for direction injection (DI) gasoline engines, and in China, also for port injection (PI) gasoline engines. Fitting a gasoline particulate filter (GPF) is often the only effective way to meet the limits.
Unlike combustible soot particulates, ash particulates accumulate in the GPF. Ash accumulation affects the GPF usage and vehicle performance over the course of vehicle life. A significant proportion of those ash particulates are engine oil derived. An in-depth understanding of these effects is vital to ensure that appropriate engine oils are developed, specified and used. This will enable original equipment manufacturers (OEMs) to consistently comply with stringent emission requirements while protecting the engine and enhancing efficiency.
In this paper the interaction of engine oil ash level and oil consumption with ash accumulation in GPF was studied in a nine-vehicle field trial. The combined effect of soot and ash particulates on GPF backpressure was included. The trial was performed under real-world driving conditions using GPF equipped vehicles. Three types of engine oil with a spread of ash levels were tested, with three vehicles using each of the oils.
Key performance parameters were monitored throughout the trial, including engine operation data and exhaust parameters for three-way catalyst (TWC) and GPF. At specific intervals during the trial emission tests on a chassis dynamometer were completed on selected vehicles using the world harmonized light duty test protocol (WLTP). The GPF post-test analysis was performed, including ash weights and bench backpressure measurements.
Ruifeng Zhang, Keith Howard, Paul Kirkman, Damien Browne, Zhihui Lu, Suhao He, Thorsten Boger
The Lubrizol Corporation, Corning Incorporated