Worldwide Harmonized Light Vehicles Test Cycle (WLTC) in Japan

Chassis dynamometer test cycles for light-duty vehicles used for vehicle emission certification/type approvals conducted in the EU and other countries according to the Worldwide harmonized Light vehicles Test Procedures (WLTP).

Light-Duty Vehicles

10-Mode Cycle

Urban driving cycle used for emission testing from light-duty vehicles, later replaced by the 10-15 mode cycle.

Japanese 10 Mode Cycle

In Japan the 10 mode cycle was used for issue of emission certification of light duty vehicles. This emission testing system was replaced by 10-15 mode cycle. The 10 mode cycle simulates urban driving conditions. The entire cycle starts with a 15 minutes warm-up at a speed of 40 km/h. The test was repeated 6 times.

JC08 Model Cycle

New urban driving cycle for emission and fuel economy measurements of light-duty vehicles. This cycle was fully replace the 10-15 mode cycle from 2011.

Japanese JC08 Cycle

In 2005 a new emission regulation was introduced in Japan called JC08 chassis dynamometer test cycle for light vehicles under 3500 kg Gross Vehicle Weight. The test represents driving in congested city traffic, including idling periods and frequently alternating acceleration and deceleration. Measurement is made twice, with a cold start and with a warm start. The test is used for emission measurement and fuel economy determination, for gasoline engine vehicles and diesel engine vehicles as well. The JC08 test had been fully phased-in by October 2011. In this test emissions were determined using weighted averages from different cycles.

  • October 2005: 12% of 11 mode cold start + 88% of 10-15 mode hot start;
  • October 2008: 25% of JC08 mode cold start + 75% of 10-15 mode hot start;
  • October 2011: 25% of JC08 cold start + 75% of JC08 hot start.

Parameters of the JC08 driving test

  • Duration: 1204 s
  • Total distance: 8.171 km
  • Average speed: 24.4 km/h (34.8 km/h excluding idle)
  • Maximum speed: 81.6 km/h
  • Load ratio: 29.7%

Heavy-Duty Engines And Vehicles

6-Mode Cycle

Two different type of 6 mode cycles were used in Japan for heavy-duty vehicles from 2.5 tons or more weight, or more than ten passengers transporting vehicles. The one type cycle was for diesel vehicles emission testing and the other cycle was for gasoline & LPG vehicles. Total emissions were expressed in ppm as a weighted average from the 6 test modes.

Japanese 6 Mode Cycle

In Japan the 6-mode cycle was used for the testing of heavy engine vehicles. This test was replaced by 13-mode cycle. The engine was tested over 6 different speed and cargo weight load conditions. The modes were ran in sequence and the duration of each mode was 3 minutes. Emissions were measured at each mode and averaged over the cycle using a set of weighting factors. The final test result was expressed as volumetric concentration in ppm mode. There were two definitions of the test modes and weighting factors. First one was for diesel engines and the second one for gasoline engines and LPG engines as well.

13-Mode Cycle

This cycle was a newer emission testing cycle for heavy duty engine vehicles that replaced the 6-mode cycles. This cycle included 13 stabilized engine modes. There were two types of the test. First one for diesel engine vehicles and the second one for gasoline engine and LPG engines vehicles which showed some differences in the test modes and had different weighting factors. Emissions were expressed in g/kWh mode.

Japanese 13 Mode Cycle

In Japan the 13-mode cycle replaced the older 6-mode cycle testing for heavy duty engines vehicles. It was used until 2005, then was replaced by the current JE05 testing method. The 13 Mode test includes a sequence of 13 steady-state modes. The emissions are averaged over the cycle using a set of weighting factors and are expressed in g/kWh. The test emphasizes slow-speed driving conditions, is characterized by low average engine loads and low exhaust temperatures. There are differences in some test modes for diesel engine vehicles, gasoline engine and LPG engines. The weighting factors are also different for each type.

JE05 Mode Cycle

This is the latest transient driving cycle in Japan for emission testing for heavy duty diesel engine vehicles and heavy duty gasoline engine vehicles that replaced the 13-mode cycle testing method.

Japanese JE05 Mode Cycle

In 2005 new JE05 emission testing cycle also known as ED12 was introduced in Japan for heavy-duty engine vehicles of 3,500 kg or more gross vehicle weight (GVW). The JE05 cycle is a transient test based on Tokyo city driving conditions for diesel engine vehicles and the gasoline engine vehicles as well. The JE05 test is defined through vehicle speed vs. time points. The duration of the test is approximately 1800 seconds, the average speed is 26.94 kilometers per hour while the maximum speed is 88 kilometers per hour.