Electric Vehicle Efficiency Trends and Insights from Calculations of Chassis and Powertrain Energy Usage in EPA Test Cycles

The number of production electric vehicles (EVs) is advancing quickly with increasingly rapid development cycles. Some manufacturers are working on 3rd or 4th generation platforms, while others are just entering the market. The rapid deployment raises questions about levels of refinement in terms of efficiency and if the technology is advancing or has become stagnated. Adequate comparisons across various manufacturers, models, and platforms require comprehensive analysis. To address these questions, this paper presents the results of calculations from mined certification databases, showing fundamental energy accountings for all EVs certified from model year 2011 to 2024. Two principal energy components are separated for analysis: consumption energy, and the required energy to drive the certification EPA speed schedules (or drive cycles). Using dynamometer road load fit coefficients and vehicle weights, a second-by-second reconstruction of the drive cycles provides the work energy at the wheels required to move the chassis for each EV. Analyzing these energies alongside consumption results isolates achievements in powertrain efficeincy from required vehicle drive energy, enabling revealing comparisons with other metrics. These basic energy assessments allow for comparisons across different models and different model years (tracking improvements over time).