Overview of Lockup Torque Converters
Unlike other converters, Lockup Converters contain a clutch. When the clutch engages, it locks the engine to the transmission input shaft, providing a direct 1:1 drive ratio.
Why would you want a lockup converter?
Really, it comes down to fuel economy. Lockup torque converters became popular when automakers were stuck in a Catch-22:
- Car buyers prefer automatic transmissions.
- Automatic transmissions are not as fuel efficient as manual transmissions.
- Automakers are required to meet government-mandated fuel economy targets.
Overdrive was one step toward better fuel economy with an automatic transmission. It allows the engine to turn at a lower RPM when the vehicle is traveling at higher speeds.
However, when the engine turns more slowly it causes the torque converter to slip, creating heat. Slipping reduces fuel economy and heat can damage the converter and the transmission. The solution is to lock the converter. Lock-up eliminates the slippage, which reduces heat and improves fuel economy.