Cummins/Tula dDSF (diesel Dynamic Skip Fire)
I have been watching this study for a while along with the Cummins ETREE project that replaced an ISB 6.7L with an ISB 4.5L hooked up to a 130kW generator pushing a 175kW motor that netted over 60% better fuel economy without any sacrifices to performance. The dDSF project was a partnership with Tula Technology which basically uses special algorithms in the ECM to skip injector firing events based on different loads.
It is sort of like variable displacement systems in gas engines, but more dynamic since it uses an array of different firing densities(up to 30) versus just 8 to 4 cylinder deactivation. The firing density will depend on torque demand. This study was done on a class 8 truck that is rarely unloaded like our pickups so the instances of low torque demand would be more frequent in our trucks and could possibly increase fuel economy, even more, when unloaded.
The best part is that not only does it not add more mechanical complexity (other than an ECM that can handle more data at a faster rate), but it also lowers emissions so current EGR/SCR systems will not be used as much while increasing fuel economy by about 20%(in a class 8 truck). I was told by some of my contacts at Cummins that this will likely be implemented into the larger medium/heavy-duty engines first and then the light-duty commercial market shortly thereafter. It would be interesting to see it work if it is eventually implemented in our pickups.
A 20% increase on the average combined fuel economy of 15.5 mpg in the current Cummins diesel pickups is an additional 3 mpg.
Cummins and Tula study of Diesel Dynamic Skip Fire
It is sort of like variable displacement systems in gas engines, but more dynamic since it uses an array of different firing densities(up to 30) versus just 8 to 4 cylinder deactivation. The firing density will depend on torque demand. This study was done on a class 8 truck that is rarely unloaded like our pickups so the instances of low torque demand would be more frequent in our trucks and could possibly increase fuel economy, even more, when unloaded.
The best part is that not only does it not add more mechanical complexity (other than an ECM that can handle more data at a faster rate), but it also lowers emissions so current EGR/SCR systems will not be used as much while increasing fuel economy by about 20%(in a class 8 truck). I was told by some of my contacts at Cummins that this will likely be implemented into the larger medium/heavy-duty engines first and then the light-duty commercial market shortly thereafter. It would be interesting to see it work if it is eventually implemented in our pickups.
A 20% increase on the average combined fuel economy of 15.5 mpg in the current Cummins diesel pickups is an additional 3 mpg.
Cummins and Tula study of Diesel Dynamic Skip Fire
