Autonomie Used to Support CAFE 2017-2025 Rule
The U.S. Department of Transportation (DOT’s) National Highway Traffic Safety Administration (DOT/NHTSA), in coordination with the U.S. Environmental Protection Agency (EPA), recently issued the final rulemaking to establish Corporate Average Fuel Economy (CAFE) standards for model year (MY) 2017-2025 passenger cars and light trucks.
In developing the standards, DOT/NHTSA made use of the CAFE Compliance and Effects Modeling System (the "Volpe model"), which was developed by DOT’s Volpe National Transportation Systems Center. The Volpe model uses numerous engineering and economic inputs in its analysis of potential CAFE standards. Some of the most significant engineering inputs are the incremental fuel-savings estimates and synergy factors associated with new technology applications. In a report to DOT/NHTSA, the National Academies of Sciences recommended that DOT/NHTSA use full vehicle simulations tools to develop effectiveness estimates and synergy factors for rulemaking analyses.
Following the recommendation, DOT/NHTSA contracted Argonne National Laboratory to perform detailed analysis. Argonne National Laboratory used its vehicle simulation tool, Autonomie, to provide DOT/NHTSA with fuel-efficiency improvement results for both transmission and electric drive technologies within the decision trees of the Volpe model. The technologies considered included the following:
- For transmissions: Automatic transmissions (up to 8 speeds), DCTs (up to 8 speeds), High-efficiency transmissions, and early torque converter lockup.
- For electric drive powertrains: 12V MHEV, Belt-integrated starter generator (BISG), Crank-integrated starter generator (CISG), Full HEV, PHEV with 20-mile all-electric range (AER) (PHEV20), PHEV with 40-mile AER (PHEV40), Fuel-cell HEV and Battery Electric vehicle with 100-mile AER (EV100)
The technology effectiveness results were used as input to the Volpe Model by DOT/NHTSA. The Argonne assumption, methodology and results are summarized in two publicly available reports: