Ram and Chevrolet just unveiled their all-new pickup trucks at the 2018 Detroit Auto Show (NAIAS): the 2019 Ram 1500 and the 2019 Chevy Silverado 1500. Both companies stay dedicated to V8 engines, but they use different strategies to improve power and efficiency.
Ram 1500 V8 with eTorque Mild Hybrid
Ram is introducing the eTorque mild hybrid system for the 2019 Ram 1500. The system is using an electric motor, which connected to the gas engine and rest of the accessories via the serpentine/accessory belt. There is a 0.430 kWh 48-volt battery pack on board that is able to store enough energy to provide a boost during initial acceleration, enable an extended use of cylinder deactivation (MDS), provide for a smooth engine start/stop functionally while stationary, and capture energy during deceleration/braking.
Yes, the Ram is still using their Multi-Displacement System (MDS) for cylinder deactivation. The V8 can run on four cylinders or all eight.
Both the 3.6L Pentastar V6 and the 5.7L HEMI V8 will have the optional eTorque hybrid system. In the case of the V6, the electric motor provides 90 lb-ft of additional torque. The HEMI gets a bigger boost of 130 lb-ft of torque. However, the overall power output ratings remain the same as before. The V6 is rated at 305 hp and 269 lb-ft of torque. The HEMI V8 is clocked at 395 hp and 410 lb-ft of torque.
The additional torque from the electric system boosts initial acceleration while the gas engine rpm are still low. Once the engine reaches its peak power band, the electric motor no longer adds power. Does it mean a faster 0-60 MPH times? We will have to wait and see.
Ram says the 2019 truck will be at least 10% more efficient than the outgoing model.
Here is a look at how Ram tests their truck engines, including the 5.7L HEMI V8 with the eTorque 48-volt mild hybrid system.
Chevy Silverado 1500 with Dynamic Skip Fire
When Chevrolet announced that the 2019 Silverado 1500 is coming back with the 5.3L and 6.2L V8 engines, they said that the truck can deactivate up to seven cylinders. There rumblings heard throughout the room with people wondering about how this would work.
Delphi and TULA developed a technology called Dynamic Skip Fire (DSF) cylinder deactivation. At the core of this technology is a sophisticated piece of software that can shut off valves to cylinders under light loads. The system is able to enable or disable firing, fuel delivery, and valve actuation dynamically (see video below for more details).
The company says that the benefits include decreased emissions, improved efficiency, and improved Noise Vibration Harshness (NVH) of the engine. Take a look at the diagram below for a claimed improvement in noise and harshness. SAE article.
The company claims a 10% reduction is CO2 emissions with DSF.
Chevrolet has not yet announced the power or MPG ratings for the 2019 V8 engines yet. We imagine they will give their V8s a slight boost in power output to keep the competition alive and well.
Could DSF cylinder deactivation improve the 2019 Silverado’s efficiency by about 10%? Chevrolet has announced any MPG figures yet. We will have to wait and see.
Here is a closer look at the Dynamic Skip Fire cylinder deactivation system in a video by Delphi / TULA.