If you have a manual transmission and step on the brakes to slow down, should you step on the clutch at the same time? You will understand after reading the following knowledge points.
1. As long as the speed is higher than the idle speed, you can not step on the clutch.
Idle speed is the lowest speed at which the engine can maintain normal and stable operation, if the speed is lower than the idle speed, then the engine is prone to shake or even stall.
Let's say your engine is idle at 800 rpm, and now you press the throttle to 3000 rpm and then release it, the engine revs will drop rapidly, but eventually it will stabilize at 800 rpm.
Don't underestimate this process, there are a lot of knowledge points in it. When you press the rpm to 3000 rpm and release the throttle, the engine will stop injecting fuel and the engine will immediately drop its speed. However, the engine computer is constantly monitoring the rpm, and when the rev is close to idling, the computer will resume fuel injection, so that the rev is maintained at 800 rpm.
You must release the throttle when you apply the brakes while driving, and if the engine revs higher than the idle speed at this time, then the engine stops injecting fuel the moment you release the throttle. At this time, there is no need to press the clutch when you apply the brakes.
However, when the engine is close to idling, it is necessary to apply the clutch before applying the brakes, because the engine needs to resume fuel injection and maintain the rpm at idle. If you don't press the clutch and only apply the brakes, it will cause the engine to rpm lower than idle, and the computer will control the engine to increase the power to maintain idling, and the engine will compete with the brakes, causing the engine to shake, the vehicle to stagnate, and even stall. In addition, many cars will increase the idle speed to 1000 rpm by default, so when the engine speed is close to 1000 rpm, you can consider stepping on the clutch.
2. What is the effect of whether or not to step on the clutch when stepping on the brake on the braking effect?
If you don't step on the clutch when you step on the brakes, then the engine braking force can help the vehicle slow down, and you can get a good braking effect when you step on the brakes a little, which not only reduces the wear and tear of the brakes, but also reduces fuel consumption when the engine brakes to stop the fuel injection. If you step on the clutch, because there is no help from the engine brake, you need to press the brake harder to achieve the same braking effect, which not only increases the wear of the brake, but also the engine will enter the idle state after stepping on the clutch, and it will consume fuel all the time.
If the brake is pressed to death in an emergency state for emergency braking, then whether you step on the clutch or not will not have much impact on the braking effect.
Many people will think that if you don't step on the clutch, there is still power on the drive wheels, which will reduce the braking effect, but in fact, this is too much to worry about. Because the engine is in a state of stop injecting fuel until the rpm is lower than idle, it not only does not provide power to the drive wheels, but provides additional braking effect. Although the engine speed is lower than idle, it will theoretically provide power to the driving wheels, but in fact, the engine output torque is extremely low at this time, and the power on the driving wheels is not an order of magnitude compared with the braking force of the braking system, so it will not adversely affect the braking effect.