What Happens When You Press the Clutch and Accelerator Simultaneously?
2 Answers
Pressing the clutch and accelerator simultaneously can damage the engine. The clutch is located inside the flywheel housing between the engine and the transmission. The clutch assembly is secured to the rear plane of the flywheel with screws, and the output shaft of the clutch is the input shaft of the transmission. While driving, the driver can press or release the clutch pedal as needed to temporarily separate or gradually engage the engine and transmission, thereby cutting off or transmitting the power from the engine to the transmission. The accelerator, also known as the throttle, is a control device that regulates the engine's power output. In piston aircraft engines, the throttle controls the carburetor's throttle opening to adjust the cylinder's filling volume, thereby determining the engine's power output. In gas turbine engines, the throttle regulates the metered fuel flow through the fuel controller, determining the thrust produced by the engine.
This operation is all too familiar to me! Occasionally pressing both the clutch and the accelerator simultaneously in a manual transmission car is actually quite common, such as during gear shift intervals. Short-term operation is completely fine, but prolonged engagement is dangerous. The engine speed will instantly surge to three or four thousand RPM or even higher, accompanied by a loud roaring sound. At this point, the clutch is in a semi-engaged state, akin to revving the engine while pressing the brake, causing the clutch disc to generate friction at high speeds and produce a burning smell. I've seen beginners practicing hill starts do this, resulting in the clutch disc smoking and being completely ruined. In fact, besides wasting fuel and damaging the clutch, prolonged operation like this can also accelerate wear on the release bearing, leading to a clunking noise during gear shifts. The safe and cost-effective approach is: decisively press the clutch when shifting gears, and immediately release the clutch and apply the accelerator after shifting, ensuring smooth power connection.
