How bad is Chinese gasoline? How high are the impurities? What can Chinese car owners do?

My brother Tai was very angry recently because he saw someone claiming that "China's gasoline is not as good as foreign countries because it contains a lot of impurities and adding it to the car will damage the car." Some so-called solutions were even given: such as "go to a gas station and see a tanker truck, just leave", such as "car owners can purchase professional imported fuel filtering equipment" and so on...

In fact, there are endless arguments that Chinese gasoline is not as good as foreign countries. After being repeatedly refuted with data, some people on the Internet are now starting to talk about the "gasoline impurities theory." We don’t know where these claims come from, but we can make a very objective argument to see if these arguments are tenable!

Is there many impurities in Chinese gasoline?

Oil filter: Do you know what this is?

Let’s first analyze how many impurities in domestic gasoline will enter the car and how they will harm the car: In fact, the gasoline from any regular gas station (I am talking about regular! Please pay attention), After being extracted from the oil tank, it will undergo several "oil-water separation" and filtration. For example, the first filtration after the gasoline is extracted is called "coarse filter". The filter element of the coarse filter is usually made of stainless steel "mat mesh".

(As for what a "mat-shaped mesh" is, let me explain it directly with a diagram! Everyone just needs to remember that the filtration accuracy of this kind of mesh is much higher than that of ordinary metal mesh) Usually the first pass The "mat mesh" density of the "coarse filter" stainless steel filter element is 180 mesh, and the corresponding filtration precision of this filter mesh is 90 microns. ——Here we can popularize the size of the unit "micron": the average thickness of an adult's hair is 0.07 mm. When converted into micron units, it is 70 microns thick.

When we cut off the hair, the cross-section of the hair is a circle, and the diameter of this circle is 70 microns (if you can’t imagine it, we can see it in the diagram). Therefore, we can imagine how tiny a particle impurity of 70 microns in diameter is. ——Okay, we know that the accuracy of the first "coarse filter" of the tanker is 90 microns.

The oil filter is divided into "first pass" and "second pass"

90 micron and 30 micron levels respectively

As long as the diameter exceeds 90 microns The particulate matter has been "removed" from the gasoline so that it can be added to the car? You are thinking too much! There is a second filter at the gas station. The filter element for this second filtration uses a paper filter element. The density of the filter element is 500 mesh, and the corresponding accuracy standard is 30 microns! (Only for gasoline, the filtration standard for diesel is 250 mesh/60 microns)

30 microns is less than half the diameter of a human hair. What is the concept? You should know that most pollen is 30 to 40 microns in diameter. After this step of filtration, the gasoline will flow from the fuel nozzle into your car's fuel tank.

There are "imported filter funnels" on the market

But the car comes with a "gasoline filter"

Be aware of some so-called "originating from the United States" "High-precision fuel filter funnel" has been very popular in China for some time. The original advertisement carried the slogan "Domestic gasoline has many impurities and needs an additional filter." But let’s go back and take a look at the filtration accuracy of those products. The low-end 127 microns, the mid-range 76 microns, the high-end 12 microns... what are they?

The filtration accuracy of low-end and mid-range products is not as "pure" as the gasoline coming out of the gas pump! So the 12 micron of high-end products seems to be able to achieve a certain filtration effect, right? In theory, this statement seems to be true.

But don’t forget, there is a “gasoline filter” in the car’s oil circuit!

So what is the filtration effect of the gasoline filter? Many articles and advertisements say that "the filtration level of automobile gasoline filters ranges from 25 to 40 microns"... But today I want to say that these are the past events of old sesame and rotten millet! !

In the era of direct injection, cars come with their own “vapor filters”

The level of filtration accuracy is so high that it’s scary!

Today’s engines have already developed into the era of direct injection in the cylinder, and the matching gasoline filters have been updated many times! Today's high-quality gasoline filters from major brands all have a precision of 2500 mesh/5 microns! For example, BMW's original filter element level is 4 microns, while top brands such as WIX or Sofima already have abnormal filter elements with a level of more than 2 microns! !

What level has this reached? Everyone! The filtration accuracy of surgical masks used in hospitals is 4 microns! Tell me, what is the practical significance of this high-end "imported fuel filter funnel" that reaches 12 microns? In fact, whether it is the "second filter" of a gas station or the gasoline filter element of a car, in addition to filtering particulate impurities, it also It has a very efficient "water removal" effect and can separate moisture. If there are irregular gas stations, "God knows"! Gasoline that is not carefully filtered will enter your fuel tank with impurities and moisture!

You see a tanker truck turn around and leave?

That’s right! But your luck is not that bad

Therefore, gasoline is filtered layer by layer from the underground tank of the gas station to the engine of your car. In the end, all the rust, dust, sludge, moisture, etc. have been Gone. ——So the "gasoline impurity theory" is not established at all! ! So is the statement "go to a gas station and see a tanker truck and leave immediately" true?

The core idea of ??this argument is: "When a tanker truck pours oil into an underground tank, it will stir up the sediment, moisture and other things deposited at the bottom of the tank." The gasoline is "dirtier". ——In fact, from the perspective of the entire filtration process of gasoline, because there is enough filtering and interception, the gasoline added to the car can still meet the standards.

But! ! ! After all, the "second filter" of the tanker can only block impurities larger than 30 microns, so impurities smaller than 30 microns will enter the car's fuel tank! Although the car itself has a "gasoline filter" that can block impurities above 5 microns, don't forget that impurities between 5 and 30 microns will be deposited on the "gasoline filter" of the car itself.

As a result, the service life of the gasoline filter element in the car will be shortened. but! ! "After the front foot of the gas station unloads the fuel, we will go to the back foot to refuel" - what is the probability of this? Does it just happen to be at this time every time you refuel? If you just happen to meet it occasionally, why bother? You turn around and drive to another gas station, and the cost of gas on the road is no longer money

Speaking of a thousand words, the key is to remember one sentence: Remember to go to a regular gas station! Also replace the fuel filter element regularly! This will be much more reliable than those so-called "tricks and home remedies"! Although the impurities in the gasoline will be blocked by the car's gasoline filter, the life of the filter will be greatly shortened. It is not worthwhile to make a small gain.

This article comes from the author of Autohome Chejiahao and does not represent the views and positions of Autohome.