Kern, B., Spiess, S., and Richter, J., "Comprehensive Gasoline Exhaust Gas Aftertreatment, an Effective Measure to Minimize the Contribution of Modern Direct Injection Engines to Fine Dust and Soot Emissions?," SAE Technical Paper 2014-01-1513, 2014, doi:10.4271/2014-01-1513.
With the growing awareness about the presence of fine/ultra fine particulates in the ambient air and their negative impact on climate and health, some regions of the world have started to look closer at the contribution of road traffic. Since Gasoline engines, in particular when injecting fuel directly into the combustion chamber, proved to emit relevant numbers of particulates, even hardly visible, the growing share of Gasoline DI engines and their small size of particulate emissions is a concern. To address the same, the EU has already set limits for the particulate number with EU6 from 2015 onwards. The US considers setting challenging limits by particulate mass. Since mass of ultra fine particulates is very low and difficult to measure, experts investigate if a measurement by number might better address the particular concern.The implementation of a coated Particulate Filter enables meeting not only basic demands during traditional emission test cycles. Also the particulate emissions during highly transient and high load driving conditions are reduced effectively.During development of coated Gasoline Particulate Filters (GPF), high priority was given to a minimum of pressure drop, to limit the negative impact on maximum power output.With currently proposed solutions, we measured no negative impact on fuel consumption during customer relevant driving conditions.Test results show, that the future particulate emission limits can reliably be met, not only after severe dyno ageing, but over long distance road durability tests as well.