Sometimes, in order to save fuel, drivers put the selector into N mode and coast. Is it right to do so?
All gearboxes have a neutral speed, which performs different functions on different types of transmissions. On manual transmissions, it is necessary to open the input and output shafts and is often used for short stops with the engine running. A machine with mechanics in “neutral” can be towed with sufficient speed and for unlimited distances. Such a box allows you to coast for a long time with the engine running.
In the last century, many motorists used this technique. He was taught in driving schools and the instructors deliberately encouraged beginners to rearrange the box selector to “neutral” every time after acceleration. The fact is that on cars of the 1950s-70s, the engine temperature grew at high speeds, water cooling did not cope well with heat removal , the coolant boiled away. Therefore, in order not to overload the power unit, many drivers drove jerkily. First – acceleration in gear, and then – coasting in neutral and cooling. The power unit switched to idle and gave off excess heat to the radiator.
Truck drivers often used this technique, but now the technique has changed and the old techniques are harmful to it . The engine cooling system has improved significantly, a constant pressure lubrication system has been invented, powered by a separate oil pump, which means that the power unit is no longer afraid of constant thrust. Moreover, turns are useful to him.
The higher the speed, the better the pump, pump and vacuum booster work. Such modes are also useful for the generator, which is driven by the engine shaft
Therefore, when coasting, it is not necessary to disengage the gear and move the selector to neutral. In addition, if the car rolls down the hill with the gear engaged, the so-called economizer is activated, that is, a software device that turns off the fuel supply, due to which gasoline consumption is reduced to zero. At the same time, the speed does not decrease, the pump and pump continue to perform their functions. It is recommended to turn on the neutral on cars with “mechanics” only when stopping.
Is it harmful to move the lever to neutral when stopping?
On machines with automatic transmissions, it is not necessary to switch on the N mode even at stops. The fact is that in classic automatic machines the transmission of torque is carried out through a fluid coupling. It allows the rotation of the input and output shafts for as long as possible without physical engagement. Therefore, when braking, the clutch absorbs the energy of rotation of the shaft, and the resulting thermal energy is removed by the cooling system.
“Neutral” in the machine is necessary only for towing the car for short distances. For example, tighten it with a cable to a tow truck or roll it manually from one end of the hangar to the other.
It is forbidden to drive in neutral on cars with a gun
The fact is that in “neutral” the oil pump and other mechanisms go into rest mode, which does not involve high loads. If the driver often moves the selector back and forth, to N and back to D, then the machine performs work unusual for him. It then turns off, then turns on, transferring a complex system of friction clutches and planetary gear sets from operating mode to parking mode and vice versa, which does not benefit the mechanics of the box.
Therefore, on machines with automatic transmissions , such as a classic hydromechanical automatic machine and a variator with a fluid coupling, it is necessary to use N only in extreme, emergency cases.
The exceptions are robotic boxes built on the basis of conventional “mechanics” and double -clutch preselective robots . N mode can be used in them, just like in conventional manual transmissions at stops. This is useful for keeping clutch discs from overheating and abrasion during stopovers with the engine running.