Most cars use a friction clutch that has all the normal parts you've probably seen or heard of before. Operated hydraulically or by cable, friction clutches use pressure plates, clutch plates (or clutch discs), and release bearings to engage and disengage the flywheel and transmission. Most cars will use a simple single-plate clutch, only higher-power engines require a multi-plate clutch to properly engage the transmission.

When the clutch pedal is depressed, the release bearing applies pressure to the diaphragm spring on the pressure plate, which releases the clamping pressure on the clutch plate and separates the transmission from the flywheel.

When shifting and releasing the clutch, the release bearing is sent back from the pressure plate, and the clutch plates are again clamped and driven by the pressure plate, allowing drive through the transmission.

Whereas wet clutches usually have multiple discs (in a car) and a source of oil to lubricate and cool the components. They are used in high torque situations where friction levels are high, so clutch temperatures can spike without some form of coolant. Any powertrain with more than 250lb-ft of torque should really use a wet clutch to avoid excessive wear on the rest of the transmission from overheating.

Dry clutches, on the other hand, are not supplied with oil and are usually monolithic. This means they can be more efficient because the lubrication causes a lack of friction between the plates in wet clutches and parasitic losses from the driveline due to the need for a pump to supply the lubricating oil. Therefore, the small coefficient of friction in wet systems is the reason for having multiple plates for effective clutch performance.

Taizhou Benwo Auto Parts Co., Ltd. is a Clutch Cover Manufacturer from China. The company is mainly engaged in Truck Pressure Plate and other clutch components.