Second-phase fuel economy standards for on-road heavy-duty vehicles in Japan

Japan’s Ministry of Land, Infrastructure, and Transportation finalized new fuel economy standards for new on-road heavy-duty vehicles as part of the government’s ongoing effort to reduce the country’s petroleum usage and greenhouse gas emissions. The Phase 2 regulation applies to model year (MY) 2025 diesel commercial vehicles with a gross vehicle weight (GVW) of 3.5 tonnes or more, as well as buses that can transport 10 or more passengers.

For tractor trucks, Japan’s requirements in 2015 and 2025—starting from a 2002 baseline—translate to annual improvements of around 1%. This is well below the annual efficiency gains in the U.S., China, and the E.U., which range from 3% to 5% per year. If Japan aims to be a leader in heavy-duty vehicle efficiency technology, it is likely that it will need to transition away from the Top Runner approach to a method for setting regulatory stringency that is more technology-forcing and requires manufacturers to push beyond current commercially available technologies.

While Japan deserves credit as the first country in the world to implement fuel efficiency standards for heavy-duty vehicles, the stringency of its first and second phase standards has lagged behind regulations in other major markets.

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