The Latest Developments in CDA Technology

Two years since Jacobs first revealed Cylinder Deactivation technology (CDA) for medium- and heavy-duty engines, the innovation is being welcomed by clean-air regulators and readied for production by engine manufacturers. New engine hardware typically takes some time to progress from the prototype stage to durability testing, validation, and production, but Jacobs’ CDA is making good progress along this path.  

CDA was unveiled in September 2018 as a new technology to reduce tailpipe emissions from 4.5- to 16-liter engines. As a bonus, CDA also improves fuel economy. Moreover, CDA has the advantage of delivering both these benefits even when the engine is operating at low load cycles or idling – precisely the real-world working conditions that tougher new emissions regulations will target. 

In fact, a whole raft of upcoming regulations – the CARB HD Omnibus, EPA Phase 2 Greenhouse Gas Emissions standards, and EPA Clean Trucks Initiative, to name just a few – will demand lower NOx and lower CO2 emissions, while no longer turning a blind eye to what the tailpipe emits at low-loads or when idling. And where CARB (the California Air Resources Board) leads, others are expected to follow, not only in North America but globally. This means CARB’s acknowledgment of cylinder deactivation as a viable "enabling technology" is internationally significant. 

Perhaps it should be no surprise then, that CDA is being evaluated or readied for production by original equipment manufacturers in the USA, Europe, China, Korea, Japan, and India. CDA shares several hardware devices with Jacobs’ High Power Density (HPD) engine brake, which is well-proven and headed for production in 2021.  As of late 2020, including HPD testing, Jacobs’ CDA components have run on 19 different heavy-duty engine platforms and in eight heavy-duty truck road tests, demonstrating its durability over more than 120,000 kilometers (75,000 miles) of driving and 15,000 hours of dyno and endurance engine testing. This has subjected CDA components to more than two billion cycles, in addition to more than 470 million cycles in fatigue and overload tests in the Jacobs engine laboratory. Such extensive testing provides reason for high confidence in CDA’s durability.  

Though CDA and HPD have different purposes, both operate by strategically disabling engine valves in cylinders. CDA does add cost to engine production, but this can be counterbalanced by reducing the size of the aftertreatment or eliminating the need for other emissions technologies. Better still, the total cost of ownership will actually be lower. This is partly because CDA reduces fuel costs, and partly because Jacobs’ CDA is designed to last as long as the engine itself. In contrast, external technologies that lower emissions by controlling after-treatment temperatures usually lower fuel economy and/or need servicing, overhaul, or replacement during the engine’s lifespan. 

At this moment, OEMs are working with us on 12 different CDA development programs, on engines with displacements of 2.2 to 15 liters. Several OEMs have progressed to the engine testing stage, and two are already at the vehicle testing stage. Proof that, in just two years, Jacobs’ CDA has established itself as an important part of the battle against emissions. Not so long ago, CDA may have been perceived as "something for the future", but that future is here!