Overview
Established in 1999, the Top Runner program in Japan sets fuel economy standards based on potential fuel efficiency improvements above and beyond the most efficient vehicles currently on the road. The 2030 targets represent a 32.4% improvement in fuel consumption compared to the 2016 fleet average. Details of the standards are covered in this ICCT policy update.
Fuel efficiency standards
New type-approved passenger cars, light trucks, and light commercial vehicles GVW ≤ 3.5 t
History
The Law Concerning the Rational Use of Energy (Energy Conservation Law) set the foundation for Japan’s fuel economy regulations. Passed in 1979 and subsequently revised, the law authorized the Ministry of International Trade and Industry (which was replaced by METI in 2001) to establish fuel economy standards for gasoline and diesel passenger vehicles (PVs). The first fuel economy for gasoline PVs were set in 1979 and applied to model year (MY) 1985 vehicles. Later on, targets were set in 1993 and applied to MY 2000 vehicles.
In 1999, revisions to Section 6 of the law established the Top Runner Program, an energy efficiency system applicable to automobiles and certain types of machinery, under the authority of the Ministry of Economy, Trade and Industry (METI). The Top Runner Program for passenger vehicles (classified as cars with a riding capacity of 10 people or less) identifies the most fuel-efficient automobile in each weight class and designates it the “top runner.” Fuel consumption targets are then set at the level of the top runner. All other vehicles are required to exceed the new target values for their weight class within three to ten years. The 1999 Top Runner Program established a fleet average target of approximately 15.1 km/L for 2010, and in 2007 a target of 16.8 km/L was set for 2015. Recently, the Japanese government issued 2020 standards that would set the fuel economy target at 20.3 km/L.
Important amendments to the Energy Conservation Law include:
- 1999: Adoption of 2010 fuel efficiency targets for gasoline passenger cars and light commercial vehicles (effective 2005 for diesel vehicles)
- 2003: Fuel efficiency standards for LPG cars (2010 targets)
- 2006: New fuel efficiency standards for heavy vehicles above 3.5 t (2015 targets)
- 2007: Adoption of 2015 fuel efficiency targets for light vehicles, including revisions to passenger car and light commercial vehicles standards, and new standards for small buses
- 2011: Set 2020 standards for passenger cars (vehicles less than 3.5 t and maximum seat capacity of ten)
- 2015: Set 2022 standards for light commercial vehicles
- 2019: Set 2030 standards for passenger cars, including battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs)
The effectiveness of the standards was enhanced by financial incentives—such as progressive taxes levied on the vehicle weight and engine displacement—that promoted the purchase of lighter vehicles. The 2030 standards do not currently provide off-cycle credits. A sticker system is in place that allows customers to identify vehicles that exceed standards.
Technical Standards
The fuel efficiency targets, expressed in kilometers per liter of fuel (km/L), are based on vehicle curb weight. Manufactures must ensure that in each financial year, the average fuel economy of their vehicles meets its respective weight standards. While fuel economy targets are mandatory, the penalties for missing the targets are minimal.
2022 LIGHT AND MEDIUM COMMERCIAL VEHICLE TARGETS
The 2022 targets came into effect in 2015 to replace the 2015 targets for light and medium commercial vehicles with GVW < 3.5 tonnes. These targets require all light and medium commercial vehicles sold in 2022 to have an average fuel economy of 17.9 km/L, which is a 23% improvement from the 2015 standard of 14.5 km/L. Targets for individual models are based on body type, fuel, transmission (manual transmission: MT or automatic transmission: AT), and weight bin. The 2022 standards are shown below:
| Body | Fuel | Transmission | Curb mass (kg) | Target (km/L) |
|---|---|---|---|---|
| Passenger type | Gasoline or diesel | MT or AT | ≤ 740 | 28.1 |
| Passenger type | Gasoline or diesel | MT or AT | 741–855 | 25.0 |
| Passenger type | Gasoline or diesel | MT or AT | 856–970 | 22.7 |
| Passenger type | Gasoline or diesel | MT or AT | 971–1080 | 20.8 |
| Passenger type | Gasoline or diesel | MT or AT | 1081–1195 | 18.5 |
| Passenger type | Gasoline or diesel | MT or AT | ≥ 1196 | 16.9 |
| Van or truck | Gasoline or diesel | MT | ≤ 740 | 21.0 |
| Van or truck | Gasoline or diesel | MT | 741–855 | 20.4 |
| Van or truck | Gasoline or diesel | MT | 856–970 | 19.9 |
| Van or truck | Gasoline or diesel | MT | 971–1080 | 19.4 |
| Van or truck | Gasoline or diesel | MT | 1081–1195 | 16.7 |
| Van or truck | Gasoline or diesel | MT | 1196–1310 | 15.1 |
| Van or truck | Gasoline or diesel | MT | 1311–1420 | 13.9 |
| Van or truck | Gasoline or diesel | MT | 1421–1530 | 12.9 |
| Van or truck | Gasoline or diesel | MT | 1531–1650 | 12.1 |
| Van or truck | Gasoline | MT | 1651–1760 | 11.5 |
| Van or truck | Gasoline | MT | ≥ 1761 | 11.0 |
| Van or truck | Gasoline or diesel | AT | ≤ 740 | 20.4 |
| Van or truck | Gasoline or diesel | AT | 741–855 | 19.8 |
| Van or truck | Gasoline or diesel | AT | 856–970 | 19.2 |
| Van or truck | Gasoline or diesel | AT | 971–1080 | 18.7 |
| Van or truck | Gasoline or diesel | AT | 1081–1195 | 16.3 |
| Van or truck | Gasoline or diesel | AT | 1196–1310 | 14.7 |
| Van or truck | Gasoline or diesel | AT | 1311–1420 | 13.5 |
| Van or truck | Gasoline or diesel | AT | 1421–1530 | 12.5 |
| Van or truck | Gasoline or diesel | AT | 1531–1650 | 11.7 |
| Van or truck | Gasoline | AT | 1651–1760 | 11.1 |
| Van or truck | Gasoline | AT | 1761–1870 | 10.6 |
| Van or truck | Gasoline | AT | ≥ 1871 | 10.2 |
| Van or truck | Diesel | MT | 1651–1760 | 16.8 |
| Van or truck | Diesel | MT | 1761–1870 | 15.9 |
| Van or truck | Diesel | MT | 1871–1990 | 15.2 |
| Van or truck | Diesel | MT | ≥ 1991 | 14.6 |
| Van or truck | Diesel | AT | 1651–1760 | 14.0 |
| Van or truck | Diesel | AT | 1761–1870 | 13.7 |
| Van or truck | Diesel | AT | 1871–1990 | 13.5 |
| Van or truck | Diesel | AT | 1991–2100 | 13.3 |
| Van or truck | Diesel | AT | ≥ 2101 | 13.0 |
The 2022 standards use a corporate average fuel economy to evaluate compliance. Plug-in hybrid and battery-electric vehicle production can help manufacturers meet requirements, but restrictions remain in place to incentivize fuel economy improvements in conventional vehicles. When a company produces commercial vehicles with alternative drive trains, the corporate average fuel economy for its diesel and gasoline vehicles must be at least 90% of its overall regulatory target imposed by the standard.
Testing
Like the 2015 standards, the 2022 standards use the JC08 cycle, which fully replaced the 10–15 mode test in 2011. A weighted harmonic average (i.e., the reciprocal of the weighted average of reciprocals of the measured data) is calculated from the cold start (weight = 0.25) and hot start (0.75) runs.
2030 PASSENGER CAR TARGETS
The 2030 targets for passenger cars came into effect in April 2020 for gasoline cars and April 2021 for newly targeted vehicles (see below).
Unlike previous standards, the 2030 standards are defined as a curve, where vehicles of curb weights less than or equal to 2759 kg have unique fuel economy (FE) standards based on curb weight. The regression is as follows: FE = -2.47×10-6 × M2 – 8.52 × 10-4 × M + 30.65, where M is curb weight. Vehicles heavier than 2759 kg have a flat fuel consumption standard of 9.50 km/L.
Manufacturers are required to meet the 2030 standards as a corporate average fuel economy. As these standards apply not only to gasoline vehicles but also to diesel, LPG, and electric vehicles, gasoline fuel efficiency equivalents are calculated using the following assumptions in tank-to-wheel (TTW) and well-to-tank (WTT) efficiency conversions:
| Lower heating value (megajoule/l) | Conversion to gasoline equivalent fuel economy (FE) | |
|---|---|---|
| Gasoline | 31.3 | 31.3/31.3 * FEG = FEG |
| Diesel | 35.8 | 31.3/35.8 * FED = 0.87 * FED |
| LPG | 24.7 | 31.3/24.7 * FELPG = 1.27 * FELPG |
| Electric | 31.3*106/3,600/EC = 8,700/EC |
| Refining | Distributing | Refueling | Total upstream efficiency | |
|---|---|---|---|---|
| Gasoline | 92.9% | 99.5% | 99.5% | 92% |
| Diesel | 93.9% | 99.5% | 99.5% | 93% |
| LPG | 97.4% | 99.5% | 100% | 97% |
| Refining | Generation efficiency | Electric generation fraction | Distributing | Total upstream efficiency | |
|---|---|---|---|---|---|
| Electric | 99.8% | 44.3% | 56% | 90.4% | 71.4% |
These assumptions can then be used to calculate the well-to-wheel (WTW) fuel economy.
| Vehicle type | Total gasoline equivalent fuel economy (km/l) |
|---|---|
| Gasoline vehicle | FEG |
| Diesel vehicle | FED /1.1 |
| LPG vehicle | FELPG /0.74 |
| BEV | 6,750/energy consumption in Wh/km |
| PHEVa |   |
| aCD=charge depleting; CS=charge sustaining; RCD=driving range (km); E1=battery capacity (kWh) | |
Testing
The 2020 targets were based on the JC08 test cycle, and the 2030 standards will be measured under the WLTP. The extra-high-speed phase is excluded from the WLTP to reflect slower driving on Japan’s more congested roads.
Links
Regulatory Documents
Contextual legislation:
Energy Conservation Law, May 2008 Revised Version
Regulatory agencies
Ministry of Economy, Trade and Industry (METI)
Additional Resources
Annual fuel economy guides (Japanese only) from MLIT
Press release on 2030 standards
