A gasoline-powered car has five main assemblies: engine, transmission, steering system, suspension, and body. Among these, the "engine and transmission" that require regular maintenance refers to the engine and transmission.
Transmission durability is always a concern for car owners. Although automatic transmissions (AT) are considered the benchmark for durability, the worst-performing transmission is not a dry dual-clutch transmission, but a continuously variable transmission (CVT). To understand which transmission is the most durable, it's essential to first understand the role of the torque converter and clutch.
The torque converter and clutch are key components of the transmission, responsible for engaging and disengaging the engine and transmission. AT and CVT transmissions use torque converters, while CVT transmissions may also use wet multi-plate clutches. Wet dual-clutch transmissions are used for engagement or disengagement during gear shifts and are lubricated by transmission fluid. Dry dual-clutch transmissions lack both lubrication and cooling systems, resulting in lower durability.
The design lifespan of a torque converter varies by brand; some brands explicitly state their torque converter design standards, such as 200,000-300,000 kilometers. However, in actual use, driving habits significantly impact the torque converter's lifespan. For example, aggressive driving may cause the torque converter to develop abnormal noises before 60,000 kilometers.
The gear components of an automatic transmission (AT) generally do not have a designed lifespan because the transmission is set with a "maximum torque capacity" to withstand the engine's maximum torque output. Therefore, the gear components of an AT transmission can be used for a long time under normal driving conditions. Conversely, a continuously variable transmission (CVT) has a shorter lifespan, mainly due to wear and tear on its pulleys and steel belt during transmission.
