An Exploratory Assessment of Electrified Propulsion Systems for Full-Size Heavy-Duty Truck Applications

Powertrain electrification could be a key enabler for compliance with future exhaust emission standards and carbon dioxide (CO₂) emissions limits or a customer facing product differentiator.

The main objective of this study was to assess the potential of electrified propulsion systems in achieving a substantial reduction in CO₂ emissions when applied to a representative full-size heavy-duty (HD) truck compared to the baseline configuration. A representative full-size HD four-wheel drive (4WD) truck of adjusted loaded vehicle weight (ALVW) 4082 kg or 9000 lbs with a 6.6 L diesel engine was simulated with various electrified drive configurations over the combined US FTP-72 (Federal Test Procedure) cycle and the Highway Fuel Economy Test (HWFET). Every hybrid vehicle configuration used in the study was designed using representative battery pack and electric drive components. Stop-start (S/S) functionality with a belt alternator starter (BAS) system provided a 2.5% benefit in CO₂ emissions over the cycle compared to the baseline vehicle. Application of various electrified drive systems resulted in a total CO₂ emissions benefit of 8.5% with a 48V P0 configuration to 25% with a high-voltage Series-Parallel hybrid over the test cycle. In addition to the CO₂ emissions benefit, the impact of an electrified drive system on vehicle performance and utility was also assessed.

This study provides an understanding of the potential benefits that can be achieved with application of various electrified propulsion systems to full-size HD trucks. The modeled CO₂ emissions reduction and vehicle performance metrics have yet to be confirmed through hardware testing.