Reasons why you should not shift to N while driving an automatic car

Shifting the gear lever to position N while the car is moving on an automatic car is due to the driver's habit of driving a manual car when he often shifts to position N and takes advantage of the car's inertia to save fuel.

While the vehicle is moving, the driver is not allowed to shift gears between the four basic gears P, R, N, D. Illustration: Lam Anh

In the city, the most common case is for drivers who are about to stop at a red light, shift to N to let the car run by inertia and slowly apply the brakes to stop the car completely, or on the highway, some people also shift to N when the car is running at high speed to gain momentum. These operations are not suitable for automatic transmission and can be dangerous when driving and damage the transmission in the long run.

The principle of driving an automatic car is not to change gears when the engine speed is higher than the standard speed in idle mode, usually this number in most car models is 700-900 rpm.

This means that the driver can only shift gears between P (park), R (reverse), N (neutral), D (forward) when the vehicle has come to a complete stop. While the vehicle is moving, the driver is not allowed to shift gears between the four basic gears P, R, N, D.

When shifting from N to D and vice versa, the automatic transmission's hydraulic pump system will engage or disengage, so constantly shifting back and forth between these two gears will reduce the life of the transmission. Even if the car stops for a short time, you should step on the brake and keep the gear stick in D position, not N.

The automatic transmission in the car regularly pumps oil to lubricate the parts in the transmission, when shifting to N, the transmission will automatically cut off the oil pump. If the car is running and shifts to N, the oil pump will not work while other components are still operating continuously at high intensity, which will lead to damage to the transmission. Not to mention the car will experience situations such as jerking or causing loss of control because the transmission does not have time to react to the difference between the current engine speed and the idle speed. According to the principle, when shifting gears, you must always step on the brake to ensure safety.

Shifting to N while the car is running will also disable electronic safety systems, such as the ESP electronic balance system, which will somewhat reduce the safety level when cornering and easily lead to loss of control.

And the Mazda car manual also has a very clear paragraph: "Do not drive the car in N gear at any time while the car is still rolling, because the engine braking function will lose its effect and damage the transmission." Thus, it is clear that car manufacturers always recommend that drivers should not shift back and forth between N and D frequently, especially not to leave the car in N gear while the car is still rolling and vice versa.