Worldwide, commercial vehicles are a growing contributor to air pollution, fuel consumption, and global-warming emissions in the on-road transportation sector. As with passenger vehicles, there are a variety of fuel, engine, and powertrain technology options for trucks and buses that can reduce criteria pollutant and greenhouse gas emissions compared with conventionally-powered diesel and gasoline vehicles. Examples of these advanced technologies include hybrid-electric, plug-in hybrid-electric, and hybrid hydraulic-powered drivetrains.
One of the challenges facing regulators is to develop or modify certification procedures so that these advanced technologies and vehicles are evaluated fairly and consistently as compared to their conventional counterparts.
This paper seeks to inform policy makers of the alternatives for moving toward more holistic approaches to testing and certifying power-train systems and complete vehicles. It describes and compares the options for testing the emissions and fuel efficiency performance of heavy-duty vehicles, discusses some of the specific regulatory challenges posed by the myriad test-method and test-cycle options that could potentially be used in a certification program, and examines opportunities for developing a world-harmonized certification procedure for heavy-duty hybrid and advanced technology vehicles.