Time-speed data points: JC08

Japanese 2005 emission regulation introduced a new JC08 chassis dynamometer test cycle for light vehicles (< 3500 kg GVW). 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 and diesel vehicles.

The JC08 test had been fully phased-in by October 2011. In the transitional period emissions were determined using weighted averages from different cycles, as follows:

  • 2005.10: 12% of 11 mode cold start + 88% of 10-15 mode hot start;
  • 2008.10: 25% of JC08 mode cold start + 75% of 10-15 mode hot start;
  • 2011.10: 25% of JC08 cold start + 75% of JC08 hot start.

The JC08 driving schedule is schematically shown in Figure 1.

[chart]

Figure 1. JC08 Test Cycle

The following are selected parameters of the JC08 driving schedule:

  • 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%