Is it fuel efficient or fuel efficient when coasting in neutral? Why?

Is it really fuel-efficient when the car is coasting in neutral?

The car coasting in neutral gear is not necessarily fuel-efficient, downhill should not slide in neutral gear, and coasting in neutral gear does not hurt the car:

1. With the improvement of the level of car manufacturing, the current car is completely different from the car of the past, just like the current new car has not run in, neutral sliding, first of all, it is illegal from the traffic law, which coach allows you to slide in neutral gear when you learn to drive;

2. The vehicle loses the traction of the engine, which will affect the handling and emergency ability, which is very unfavorable to safe driving, when the car is at high speed, step on the neutral gear, the engine speed will come down immediately, so as to achieve the purpose of fuel saving, but the car is not the same now, the computer will control everything, lift the throttle at high speed, the engine will automatically stop injecting, use the engine's anti-support, continue to move forward, when the engine speed drops to a certain level, the engine will continue to inject oil;

3. But if you pick up neutral gear at high speed, then no matter whether you keep driving or not, the engine is in idle state and has to be injected. Therefore, high-speed driving with gear coasting is more fuel-efficient than neutral coasting, and safer, but this is only in the case of high-speed, long-term low-speed driving (generally not more than 30km h), neutral gear is more fuel-efficient than belt gear slide.

From the fuel supply logic, I will tell you the reasons for the fuel saving of neutral coasting and gear coasting. Let's talk about it first, this has to start with the fuel supply mode of the engine, and there are two main fuel supply methods for the gasoline engine models driving in the society, the old car carburetor fuel supply mode, and the new car electronically controlled fuel injection mode. The carburetor fuel supply mode is to rely on the low pressure formed when the engine intakes the fuel into the combustion chamber for combustion, the method of controlling the amount of oil is to use the measuring hole, the cross-sectional size of the measuring hole determines the amount of oil sucked in, the air intake is controlled by the throttle, the air is mixed with gasoline and enters the combustion chamber to do work, and there are other auxiliary systems such as idling, rapid acceleration, and full-load fuel supply.

Electronically controlled fuel injection mode, referred to as EFI, it is divided into a single point, multi-point, sequential a variety of ways, here is his working principle, it is completely different from the carburetor fuel supply mode, it is by the fuel injector to the intake pipe to inject fuel to supply, the fuel injector is controlled by the computer solenoid valve of the current to control the time of the fuel injector, which also controls the amount of fuel injection, and at the same time corrects the amount of fuel injection according to the signal from each sensor of the engine, so as to achieve the purpose of accurate control. Let's talk about the treatment of the two oil supply methods in the case of two gears and neutral gears. Carburetor, regardless of neutral gear, or with gear, as long as there is gas through, there will be corresponding gasoline into the engine combustion, with gear is the engine is pushed by the vehicle, the speed of the engine is not low, so although the throttle is closed, the amount of air entering is limited, but the engine intake formed a lot of low pressure, gasoline is still a lot of inhaled, this is a lot of old cars with gear as soon as the gun is fired, is because a lot of gasoline in the engine is not burned clean, into the exhaust pipe combustion caused.

But the neutral gear is different, the neutral gear is idling, which is definitely more fuel-efficient than this, so the car's neutral gear of the carburetor is fuel-efficient, and the belt gear is not fuel-efficient at all. EFI engine, neutral gear is idle fuel supply, there are two situations with gear, one is when the vehicle is driving at high speed, suddenly the computer detects that the throttle valve returns to the speed position, it thinks that it enters the state of sliding with gear, for fuel economy, the computer will stop injecting, completely let the car push the engine back, the computer detects that the vehicle driving speed drops to the specified value, the computer controls the injector to continue to inject fuel to maintain the operation of the engine, during which you refuel it will immediately resume the fuel supply, This is the basis for the argument that coasting with gears can save fuel. However, it should be noted that in general, for example, if you drive at a speed of 60 kilometers and you coast with gear, this function will not start, because when the speed is low, the engine will completely stop injecting fuel and cause the car, if the oil supply brake can not be restored, it will also be affected, so the speed set by the manufacturer is very high, and the usual low-speed driving is not fuel-efficient at all.

Therefore, the EFI engine is fuel-efficient for high-speed coasting, and low-speed coasting is fuel-efficient. Therefore, the carburetor car is fuel-efficient in neutral gear, and the EFI car should make good use of the characteristics of high-speed and low-speed coasting to save fuel in the middle of the gear in order to achieve the most fuel-efficient, hehe! But it's not recommended, how much can you save, or safety is the most important!

1.Driving in neutral not only violates traffic bans, but also costs fuel for cars with EFI engines.

2.The control system of the EFI engine has the function of deceleration and oil reduction or oil cut-off, this kind of car can rely on its own design to achieve the effect of fuel saving at high speed.

The EFI vehicle is not fuel-efficient when coasting in neutral gear. Because the EFI car will not stall when the engine is in neutral, there will be idle speed, which is what we know about idle fuel consumption. In gear, as long as the engine speed is not lower than 900-1000 rpm, the engine does not need oil at all.