What kind of fuel is suitable for the car, there must be written on the user manual and the fuel tank cap, and the family car is generally 92, 95.
Some cars with more powerful performance, the manual and the fuel tank cap It is possible to mark the use of 98, or it is recommended to use 98.
This is actually a bit like: You see that kind of very powerful hunk in the gym, with a beer barrel as big as his waist. He said that this thing is protein powder, which is generally not practical for us. .
How is the engine gasoline label determined?
The gasoline label indicates the octane number of gasoline, which is the anti-knock performance. I have talked about this many times before , I won’t repeat it.
As for the specific gasoline of the engine, it has a lot to do with the compression ratio of the engine.
The compression ratio is an important parameter to measure engine performance. It refers to the ratio of the volume in the cylinder when the piston is at bottom dead center and top dead center.
reflects the extent to which the engine can compress the combustion working fluid. The harder the compression, the theoretically more energy will be exploded.
It is a spring or... You just think this is a syringe, right? You press the syringe to the end, and then draw it over. Isn’t it possible to draw some water? The volume of water in this section is this ratio.
The harder the compression, it means that when the engine is working, the higher the pressure in the cylinder, the easier it is to knock. It requires gasoline with better anti-knock properties to play power.
Generally speaking, the higher the compression ratio, the higher the gasoline grade.
Or take the spring just now as an example: the harder you press, the stronger the spring will rebound? Correspondingly, the quality of the spring must be good, otherwise it will be easily broken.
Chang'an University has a paper, "Research on the Anti-knock Performance of Vehicle Fuel and Its Testing Method", there is a data record.
When the compression ratio is between 7.5 and 9.5, every increase of 1 unit will increase the octane rating by 4 units.
However, the reference significance of the engine compression ratio is not as great as before, mainly because there are many advanced technologies that make the engine compression ratio look really beautiful.
is like: Now you go to watch videos and watch live broadcasts online, there are beautiful young ladies and beautiful girls everywhere, right? Of course, we don’t know if she has added filters.
For example: Mazda, Toyota, Volkswagen, these so-called "high compression ratio" family cars, most of them use a thing called "Atkinson cycle" to achieve high compression ratio.
This compression ratio is called the "geometric compression ratio", which is just the ratio of the maximum and minimum volume of the cylinder.
In actual work, the intake valve will remain open at the beginning of the compression stroke, and some gas will be discharged as the piston moves up. The effective compression ratio is not as scary as we seem.
is like saying: You participate in the Big Stomach King competition, "Ahhhhhhhhhhhhhhhhhhhh" over there. In other words, if you fight with others, the burger is falling while you are eating.
While you are drinking, the wine leaks out of your mouth, and even you deliberately spit out, which is almost the same.
What kind of car is suitable for 98th oil
Generally speaking, a car with strong power and a high compression ratio means gasoline with better explosion resistance. To cooperate.
Models with high compression ratio
Here, let’s take a supercar as an example. The compression ratio of this car is generally higher.
Ferrari 812 naturally aspirated engine with a compression ratio of 13.6, which is quite high. The Porsche GT3 RS also has 13.3, which far exceeds the 9-11 standard for family cars.
For these models, only 98 gasoline can exert full performance. Even if there are some models, it can add 95, which will not be bad, but the performance is also discounted.
For example: It is written in the Porsche manual that using 98# gasoline can make the engine achieve the best performance and lowest fuel consumption.
But these fuels cannot always be supplied. To be honest, so when using No. 95, pay attention to the fact that the engine knock control system will automatically adjust the ignition timing, which may reduce the engine power And increase fuel consumption.
is available and discounted.
This is the most important thing: adjusting the ignition timing can suppress knocking, but the strength is less.
"Journal of Xihua University" has a paper, "Research on the Influence of Different Octane Number Gasoline on Turbocharged Direct Injection Gasoline Engines" has made an experimental record. After
engine adjusted the ignition timing, the maximum explosion pressure of internal explosion was reduced, the crank angle corresponding to the maximum explosion pressure was also delayed, and the expansion ratio of the mixture was also reduced.
The combustion duration is increased, and the combustion speed is slowed down, which will cause the thermal efficiency and combustion capacity of the engine to decrease.
Anyway, you don’t need to remember so many things, that is: the power has become worse and the fuel consumption has become higher.
What does this look like? That is: a person who doesn't eat spicy food suddenly went to Chongqing or Chengdu. The body does have its own regulating function, so that he would not be hospitalized directly after eating hot pot.
But if you have diarrhea in the toilet for a week, it is almost the same.
Models with super high turbo pressure
Except for models with super high compression ratios, some models with super high turbo pressure The performance car, the manual and the fuel tank cap are also marked: 98.
. This is generally the case. The reason is the same. The ultra-high compression ratio needs to be high-marked because: the pressure is hard, the pressure is high, and it is easy to knock. Although the
turbocharged car does not seem to have a very high compression ratio, the turbocharger has already compressed the air in advance, and the pressure inside the cylinder is also higher than the naturally aspirated air.
is like: self-priming eats ordinary biscuits, and it doesn’t feel much after a bag; turbocharged eats compressed biscuits, they don’t look very big, just a little bit of water, the whole belly is fully opened, immediately It's full.
The degree of air compression is different, because in the end it is not the pressure? In the front it was "suppressed", now it is "it was very cruel to you."
For example: the 2.0T engine of the Mercedes-Benz A45 S AMG model has a compression ratio of 9, which sounds super ordinary, with a turbo pressure of 2.1 Bar.
Ferrari F154 twin-turbocharged engine, the turbo pressure is 2.4Bar, which is even more powerful, McLaren P1 is also 2.4Bar.
You should know that ordinary family cars, for example: BMW's B48 engine, the low-power version is only 0.6Bar, and the high-power is 1.4Bar.
Volkswagen classic model EA888, the high-power version is only about 1.2Bar.
The supercharging pressure of these performance cars is basically double that of family cars.
Can a family car use 98?
So now, we can see that a car with strong power can add 98, but a family car is not very recommended.
4da1The main reason for a# is 98, 95, 92, and there is only a difference in blast resistance. The calorific value is not much different, and the degree of burn resistance is the same.is 98 because the anti-knock performance is slightly better, and it has a little fuel-saving effect.
I said before: about every increase of 1 octane unit, the average fuel saving is about 1%, and this is not all cars have this effect, anyway, it is not saving money.
The State Key Laboratory of Automotive Safety and Energy of Tsinghua University published a paper, "The full vehicle test of the effect of octane number on the fuel consumption and emissions of modern gasoline vehicles" gave a conclusion.
The high-grade fuel-saving effect is only useful for engines that adopt newer technologies such as supercharging, miniaturization, and direct injection.
For vehicles with relatively backward engine technology, the label change has no obvious impact, and older models don’t have to join in the fun.
Smart phones are very convenient. Your grandpa and grandma are both 109 years old. They can basically hear, can use the elderly phone, and can dial a few family members smoothly.
You can teach him how to use other apps, then who is embarrassed? This is difficult to tell, right?
What mark gasoline is added depends on the design of the engine
So in general, what mark gasoline is added to the car depends on the design of the engine.
Generally speaking, the higher the compression ratio and the higher the turbine pressure, the more high-grade gasoline is needed.
92 to 95, can it save fuel?
The general family car really does not use 98, so how do we choose 95 and 92?
Some friends said: "No. 95 is more fuel-efficient than No. 92." Is it true?
92 is added by half, and half a box of 95 is added on a whim. Will it become 93.945 gasoline? Can it be used?
Is it necessary to add 95 to a family car with 100,000 yuan, it says 92, and vice versa, it says 95, can I change it to 92?
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