Cummins said it is ready to meet the next step of Euro 6 emissions control with clean diesels now certified to the more stringent Phase-D regulation, following a two-year development and test programme. The B4.5, B6.7 and L9 engines with a 112-298 kW range for bus and coach applications will move to full production status at the Cummins Darlington facility in the UK before Phase-D takes effect on Sept. 1, 2019.
Introduced by Cummins at the UITP Global Public Transport Summit in Stockholm, Sweden the Euro 6 Phase-D engines achieve nearer-to-zero emissions, representing an incremental step towards Euro 7 regulations, anticipated to take effect after 2025, the company said.
The Phase-D regulations are particularly relevant for bus operations, as they focus on tighter control limits for Oxides of Nitrogen (NOx) emissions during lower speed city operations, as well as under cold engine start conditions. In addition to emissions test cell verification, the Phase-D regulations require on-road testing to capture real-world measurement.
Duty cycle-based testing using high precision Portable Emissions Measurement systems (PEMs) installed on Cummins-powered buses has indicated a 25% reduction in NOx emissions, compared to the Phase-A engines when Euro 6 was first introduced in 2015.
“With exceptionally low NOx emissions, our latest Phase-D products will help bus fleets improve air quality and align with the recent arrival of the London Ultra Low Emission Zone and other Clean Air Zones being established in cities across Europe,” said Ashley Watton, Cummins Director — On-Highway Business Europe.
“To achieve Phase-D certification we focused on the emissions control logic and developed a new algorithm for the management system. By refining and retesting the software over a two-year period, we were able to avoid making any hardware change to the engine or exhaust aftertreatment.
“Phase-D development work required a substantial investment by Cummins, but it does mean our customers retain the benefit of a proven product with identical performance to those they experience today. In terms of vehicle integration, this is no need to re-engineer the Euro 6 installations as our Phase-D engines offer a seamless, drop-in solution,” added Watton. Pictured is the Cummins B6.7 Euro 6 Phase-D engine.