New Standard for Measuring Emissions and Fuel Economy of PHEVs from SAE

As PHEVs are gaining in popularity worldwide, SAE International has launched a new revised standard for measuring the exhaust emissions and fuel economy of such vehicles. The recently released revised standard is dubbed “J1711 – Recommended Practice for Measuring the Exhaust Emissions and Fuel Economy of Hybrid Electric Vehicles, including Plug-in Hybrid."

The new standard establishes uniform chassis dynamometer test procedures for hybrid-electric vehicles that are designed to be driven on public roads.

According to SAE, an HEV is defined as a road vehicle that can draw propulsion energy from both of the following sources of stored energy: 1) a consumable fuel and 2) a rechargeable energy storage system (RESS) that is recharged by an electric motor-generator system, an off-vehicle electric energy source, or both.

Michael Duoba, who is an automotive engineer with the U.S. Department of Energy's Argonne National Laboratory and also chairman of the SAE International Hybrid J1711 Task Force, is the one who created the revised standard.

"Until now, the fuel economy claims for plug-in hybrids were not calculated according to similar procedures, making car-to-car comparisons virtually impossible,” Douba said in a release. “What makes this procedure – and other SAE-developed recommended practices – significant is that EPA typically considers them as the basis for the automotive regulations it promulgates. Ultimately, the consumer benefits with valuable vehicle information that can help guide a purchase decision."

Consumable fuels included in the new standard are limited to petroleum-based liquid fuels (e.g., gasoline and Diesel fuel), alcohol-based liquid fuels (e.g., methanol and ethanol), and hydrocarbon-based gaseous fuels (e.g., compressed natural gas).