Are We Testing Vehicles the Right Way? Challenges of Electrified and Connected Vehicles for Standard Drive Cycles and On-Road Testing

Standard driving cycles have been the method of choice for testing vehicle performance for decades, both in research and at the regulatory level. These methodologies offer the significant advantage of test reproducibility, allowing for consistent comparisons between vehicles. However, their inability to reflect real-world driving conditions has become increasingly evident. This issue was first exacerbated by the advent of hybrid and plug-in hybrid vehicles, which introduced new complexities in powertrain operation. Legislators attempted to adapt testing procedures to account for electric energy usage in emissions assessments, but these efforts have largely failed to address the technical challenges posed by modern vehicles. As a result, the gap between real-world fuel consumption and type-approval values has continued to grow. The introduction of ADAS technologies has further widened this discrepancy, as standard driving cycles are no longer capable of accurately representing modern vehicle performance. In light of these challenges, this paper critically evaluates the limitations of standard drive cycles and on-road testing procedures, explores how hybrid and connected vehicles further complicate performance assessment, and proposes directions for improving these methodologies.