CLTC Range testing

The CLTC is a driving cycle that simulates the typical driving conditions and patterns of Chinese drivers.

It was developed by the China Automotive Technology & Research Center (CATARC) in 2020, and it is expected to replace the previous test cycle, called the China Automotive Test Cycle (CATC), which was based on the outdated New European Driving Cycle (NEDC). The CLTC aims to provide more realistic and accurate range estimates for EVs in China.

The CLTC-P contains a total of 11 short trips (including 7 short trips in the low-speed phase, 3 short trips in the medium-speed phase, and 1 short trip in the high-speed phase) and 12 idle segments, with a total duration of 1800 seconds.

Phase 1Phase 2Phase 3Total
Duration, Seconds6746934331800
Stop, seconds398
Distance in meter24505910612014480
Percent stop22.11%
Max speed48.171.2114114
Average speed w/o stop53.5
Avg speed w stop1330.750.846.5
Maximum deceleration m/s^2-1.4-1.5-1.5- 1.44
Max acceleration m/s^21.471.441.06

How is the CLTC performed?

The CLTC is performed on a dynamometer, which is a device that simulates driving conditions by placing the vehicle on rollers and measuring its performance. The vehicle is tested in a laboratory under controlled temperature, humidity, and pressure conditions.

The testing procedure starts with fully charging the vehicle’s battery and leaving it parked overnight. The next day, the vehicle is driven on the dynamometer following the speed profile of the CLTC until the battery is completely depleted or the vehicle cannot maintain a minimum speed of 40 km/h (25 mph). The total distance traveled by the vehicle during the test is recorded as the preliminary range estimate.

However, this estimate is then adjusted by a correction factor to account for variations in driving conditions, such as temperature, terrain, and driver behavior. The correction factor is based on data collected from real-world driving by EV owners in different regions of China. The final range estimate is the product of the preliminary range estimate and the correction factor.

How does the CLTC compare to other test cycles?

According to Chinese sources, CLTC estimates are mostly higher than both WLTP and NEDC range figures. For example, an electric vehicle that has a 398 km WLTP and a 484 km NEDC range estimate scored more range (509 km) when CLTC testing procedures were followed. This suggests that the CLTC is more generous than other test cycles in estimating EV range.

However, some experts argue that the CLTC is not necessarily unrealistic or inaccurate, but rather reflects the specific characteristics of Chinese roads and drivers. They claim that Chinese drivers tend to drive faster and more aggressively than European drivers, especially on highways and extra-highways. They also point out that China has a large land area with diverse terrain and climate conditions, which can affect EV performance and range.

Therefore, they suggest that the CLTC is more suitable for evaluating EV range in China than other test cycles that are based on foreign driving patterns and environments. They also recommend that consumers should compare EV range estimates based on the same test cycle rather than different ones to avoid confusion and misunderstanding