Why do automatic cars have neutral?

Why do automatic cars have neutral?

If you are familiar with driving automatic cars, you’ll notice a gear choice of Neutral between Reverse and Drive that never seems to get used.  In fact, you might be wondering why Neutral is there at all.  After all, when you stop and park the vehicle, you would normally select Park and apply the handbrake.

Park and Neutral are basically the same.  With Park, there is a locking mechanism, called a ‘pawl’ which stops the transmission from turning, and should only be used when the vehicle is stopped.  With the transmission locked in Park, always apply the handbrake to prevent overloading and damage to the transmission.  So Neutral is the same as Park but without the locking mechanism.

So why use Neutral at all?  Generally, the main purpose of Neutral on an automatic is for towing or pushing the car.  You won't be able to push or tow the car with the transmission in Park.  And, if you tow the car with the transmission in gear or in Park and the drive wheels are in contact with the ground, you'll ruin your transmission and possibly damage the tyres as well.

Neutral may be helpful in emergency situations.  For example, if the accelerator or throttle was stuck and the engine is continually revving, the brake alone may not be effective enough to slow and stop the vehicle especially if you are travelling along a high-speed road. Switching off the engine will cut the power to the steering and brakes, making it extremely difficult to stop the car without any damage.  By shifting into Neutral, this will not stop the engine from revving, but it will make it a lot easier to slow and stop the vehicle.