Cummins, Tula test ‘dynamic’ cylinder deactivation

Tula's Dynamic Skip Fire technology already used in light-duty gasoline engines shows potential in heavy-duty diesels to significantly reduce NOx emissions.

Tula Technology has supplied the control software for “dynamic” cylinder deactivation in gasoline engines since 2018, launching in General Motors' 5.3- and 6.2-L units powering the Chevrolet Silverado and GMC Sierra pickup trucks. Compared to the common two-mode implementation in engines, where either all of the cylinders are firing or a fixed number of cylinders are deactivated, Tula's Dynamic Skip Fire (DSF) makes all of the cylinders selectively “deactivateable,” according to Scott Bailey, president and CEO of Tula Technology.

Seventeen steady-state patterns are available in the GM gasoline V8s, but the technology continuously operates whether in a “pattern” or not. Cylinder-deactivation fuel-economy gains in gasoline engines can be doubled with dynamic deactivation, Bailey said. In the case of the Silverado's V8, that's an up-to-15% improvement in fuel consumption compared to about 5-7% with two-mode deactivation.