The coasting is a mode in which the lever of the mechanical transmission is in the neutral position. Detail of gearshift in this case are in a state of rest, with the exception of the drive shaft. If advanced again and the clutch pedal, the engine turns into a stand-alone device, running on idle.
Some drivers to save fuel during coast down practice shutting down the engine. As a result, the car represents, figuratively speaking, a "trolley" moving by inertia at the expense of previously received speed.
The coasting drive used careless drivers on long descents or when approaching intersections and other road sections, where you must gradually slow down.
The conventional wisdom about fuel economy when coasting has come to us from the last century, when the engines were imperfect. What do we have now?
When the car is turned off, shifting the engine is idling, consuming fuel in an amount of from 2 to 3 liters per 100 km. If you leave the gear engaged and releasing the accelerator pedal, that is, to switch to engine braking, fuel supply to the engine almost completely stops, and fuel consumption will be close to zero.
This is very easy to see if you have a car on-Board computer with the function of displaying the current fuel consumption. Really, when you release the gas pedal the device shows almost zero consumption of gasoline or diesel fuel.
As a result, wanting to reduce fuel consumption through the use of coast down, the drivers only increase.
Another common misconception is that the braking effect when the transmission is significantly higher than when. When driving with the switched off transfer, if necessary to dramatically slow down or stop, braking only takes part of the main braking system of the vehicle. It is very high risk of locking the wheels and losing control of the machine due to the decrease in coupling of wheels with road.
In the case of the selected gear working the engine will not allow the wheels any chance of a lock and combined braking system, which includes the engine brake and the service brake system, will help achieve minimum stopping distances.
Especially dangerous braking is turned off transfer in conditions of wet road surface or ice, when the appearance of even a small dry stretch of road followed by the uneven distribution of braking forces to the wheels can cause skidding, is fraught with a traffic accident.
Saving resources to the clutch and gearbox
Deeply mistaken are those who think that letting the car coast down, save resources of the clutch and gear change. The frequency and intensity of the use of a clutch pedal and gear lever on the durability of the gearbox and the clutch is almost not affected.
Much more damage these mechanisms cause incorrect operation of the clutch and breaking the sequence of actions when switching from one gear to another.
"Lovers" for a long time to hold down the clutch pedal I'd like to remind that pressing the clutch pedal only valid for a short time, needed to switch to the next gear. In all other cases, to detach the engine from the drive wheels need to squeeze the clutch and turn neutral.
Based on the foregoing, the question arises: "If driving coasting doesn't save fuel, doesn't increase the braking performance and does not affect the resource mechanisms, is there any sense in using it?"
In our opinion, the reel is only acceptable in the final phase of the movement when moving with the minimum speed on a dry road, a few meters is planned to complete stopping of the vehicle.
Good luck to you! No nail, no wand!