Is it possible to save fuel and extend the life of the automatic transmission by switching to neutral mode in a traffic jam?

On the Web, disputes are raging about how important it is, having stopped at a traffic light, to move the “machine” selector to the neutral position “N”. Like, this way you can increase the resource of the unit, and even save fuel. The experts of the portal "AvtoVzglyad" figured out whether this is really so.

And to begin with, we recall that in the classic "automatic" a torque converter is installed, consisting of two parts - a centrifugal pump and a centripetal turbine. Between them is a guide vane - a reactor. The centrifugal pump wheel is rigidly connected to the engine crankshaft, the turbine wheel is connected to the gearbox shaft. And the reactor can either rotate freely or be blocked by a freewheel.

Is overheating so bad?

In such a transmission, a lot of energy is spent on “shoveling” the oil with a torque converter. The pump also consumes it, which creates working pressure in the control lines. Hence all the fears of drivers about overheating of the transmission, because the oil in the "box" heats up. Like, by moving the lever to "neutral", there will be no overheating. But you shouldn't be afraid of it. If the replacement of the oil and filter was not delayed, the "machine" will not overheat.

And in general, this unit is quite reliable. From my own experience I can say that the "automatic" Chevrolet Cobalt, even with oil starvation, when strong jerks appeared during switching, courageously withstood this execution and did not break. In a word, to overheat the automatic transmission - you have to try very hard.

By the way, the "automatic" can extend the life of the engine, because the torque converter is an excellent damper. It can dampen strong vibrations that are transmitted from the transmission to the motor.

Should I switch to neutral?

Let's figure it out. When the driver moves the selector from “D” to “N” in a traffic jam, the following process occurs: the clutches open, the solenoids close, the shafts disengage. If the flow has started, then the driver again transfers the selector from "N" to "D" and this whole complex process is repeated over and over again. As a result, in the "torn" city traffic, the constant jerking of the selector will only lead to gradual wear of the solenoids and friction clutches. In the future, this will come back to haunt the repair of the "box". There is no need to talk about any savings in this case.

So it's better not to touch the transmission selector once again. And to crawl in a traffic jam, put the "automatic" in manual mode, turn on the first or second gear. So the “box” will be easier: after all, the fewer switches it has, the better.