[Original of Truck House] Some time ago, I saw several netizens retrofitting their vehicles in the forum, in order to improve the purity of intake air and thus improve the service life of the engine. From the post, we also see that some netizens have questioned this behavior. They think that installing air filter will increase the intake resistance of the engine, so it is not good for the engine and will increase the fuel consumption of the vehicle.
In the end, whether the air filter will affect the engine or not, we don’t make any judgment here. However, whether the air intake will really be blocked as mentioned by netizens can actually be displayed intuitively with a little thing called "maintenance indicator". Let’s talk about its principle and function first.
● What is the air filter maintenance indicator?
The big picture above shows the air filter maintenance indicator assembled by trucks in the early days of liberation; The left side of the picture below shows the popular electronic sensor on the truck now; On the right is Isuzu truck air filter maintenance indicator.
The negative pressure in the air inlet pipeline is directly affected by the slight cleanliness of air filter, and the clean negative pressure is small, otherwise the negative pressure increases. The air filter maintenance indicator is generally installed at the air outlet end of the air filter, and its internal slider changes position due to the change of negative pressure in the air inlet pipeline. Users can intuitively get the answer whether the air filter needs maintenance only through the air filter maintenance indicator.
We have made a set of demonstration pictures here, which respectively illustrate the display content of air filter maintenance indicator and the maintenance of air filter. From left to right are:
1. The indicator window is green, indicating that the air intake is smooth and the air filtration is in good condition.
2. The indicator window is green+yellow, indicating that the air intake is smooth, and the air filter does not need maintenance temporarily.
3. The indicator window is yellow+red, indicating that the air intake is slightly blocked and the air filter can be maintained.
4. The indicator window is red, indicating that the air intake is seriously blocked and the air filter must be replaced.
With the application of EFI technology in vehicles, the air filter maintenance indicator on most vehicles has been changed to inductive type. However, Xiao Bian believes that such an intuitive thing is more reliable. If a friend with an air filter is worried about the excessive intake resistance, he can buy one and install it in his car to check whether the intake resistance of the car is within the normal range. (Text/Figure Huo Jingchun)