Why can CVT only use gravity oil change?

[BriannaLee]

Due to the complex internal structure of traditional automatic transmissions, including the torque converter and 'mushroom head' mechanism, the specific situation is as follows: 1. Gravity oil change: Simply using gravity oil change cannot effectively drain the old oil, so a circulation machine is required for oil change. 2. Others: CVT, on the other hand, uses two trapezoidal pulleys and a steel belt for speed variation, and its internal structure is not as complex as traditional transmissions, so gravity oil change is sufficient. Additional information: The internal mechanism of CVT transmissions is indeed slightly simpler than traditional AT transmissions, but there are still many areas inside CVT transmissions where dirt can accumulate, and simply using gravity oil change cannot effectively drain the old oil. The same principle applies to dual-clutch transmissions.