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Heavy Truck Fuel Efficiency Standards: Priorities for Phase II

December 16, 2011 - 12:29pm
By Siddiq Khan, Senior Researcher

EPA and NHTSA only finalized the first fuel efficiency and greenhouse gas standards for heavy-duty vehicles in August but soon must begin thinking about the next round. Today ACEEE released a new report, Heavy-Duty Vehicle Fuel Efficiency and Greenhouse Gas Emissions: The 2014–2019 Standards and a Pathway to the Next Phase, offering recommendations in a dozen key areas. Top priorities include ensuring that advanced efficiency technologies will be recognized and incentivized by the program, further tailoring the program to reflect the real-world behavior of trucks and buses, and providing meaningful fuel efficiency information to buyers and the public.

The first item on the agencies’ plates should be adding trailers to the mix, since readily available aerodynamic and tire improvements can deliver big savings in short order, especially for tractors pulling van trailers. Preparatory work for the next phase of the program should also include resurrecting the national Vehicle Inventory and Use Survey (VIUS) to ensure adequate knowledge of the trucks on the road and their driving patterns, and developing better, more accessible vehicle simulation tools to reduce the burden of physical testing of the enormous array of heavy-duty vehicles sold.

Once these steps have been taken, the agencies should steer the program toward treatment of vehicles as integrated systems, rather than a collection of components. That in turn will help drive better transmissions,driveline efficiency, and powertrain integration. We also recommend further segmentation of the vehicle market, especially for vocational vehicles such as delivery trucks, refuse trucks, transit buses, and utility trucks, so that test cycles and standards can better reflect the actual usage of these vehicles. 

The initial standards rely upon well-developed technologies that pay back their up-front costs within a couple of years. In the next phase, technologies with higher up front costs that can deliver big savings in the longer term, like hybrids and advanced engine technologies, will likely offer the greatest opportunities. Especially given the short periods of new vehicle ownership common in some segments of the market, longer payback periods represent a challenge to advanced technology adoption. Meeting this challenge will require the provision of reliable, detailed, buyer-specific information on vehicle performance in both the new and used vehicle markets.

Finally, to the extent possible, the agencies should seek to achieve consistency with other regions of the world developing heavy-duty vehicle fuel efficiency and greenhouse gas reduction programs. Shared measurement protocols, test cycles, simulation models, and perhaps stringency of standards can help to create a global market for advanced technologies and thereby speed their adoption. 

UPDATE: Click here for a fact sheet summarizing the key requirements of the heavy-duty standards.