1. Introduction
rising oil prices so that consumers have to pay attention to fuel consumption issues. Speaking on gasoline, compared to 97 # 93 # Will more fuel-efficient? Two kinds of fuel are not careful mix what are the consequences? I believe we all want to know. Fuel index 1 compression ratio:
car selection is the primary standard grade of gasoline engine compression ratio, but also the core of contemporary automotive energy-saving targets. By running the engine cylinders’ intake – compression – combustion – exhaust – suction “This cycle of movement composed of the piston stroke than the farthest point and the nearest point when the cylinder volume is compressed ratio. The best way to effect the lowest cost to reduce fuel consumption is to increase the compression ratio of the engine. Improve the compression ratio only changes the piston stroke, the more powerful mixing and gas compression, the greater its combustion reaction, the more complete combustion. But the compression ratio is not easily active, because there was another indicator of cooperation, namely gasoline antiknock index, also known as the octane number, namely gasoline label. 2, the knock antiknock:
is generally believed that, when the piston is at about 10 degrees after top dead center of the stroke, the maximum combustion pressure, maximum efforts to promote the piston (like a swing, reaching swing a little hard fastest after the highest point). For example, 1000 rpm when the combustion process is equivalent to the crank angle of 20 degrees, 10 degrees, that is pre-ignition engine, the most powerful. And to 4000 rpm, the faster movement of the piston, the combustion process is equivalent to a crank angle of 60 degrees, 50 degrees requires pre-ignition, so the speed increases, the ignition advance is increasing. Will eventually reach a speed, not oil and gas ignition to burn up, this is the knock. Label
gasoline determines the detonation point sooner or later, in fact, is the power determines the size of the engine. Fuel anti-knock performance over its composition varies. The higher fuel anti-knock properties, may also be some high compression ratio of the engine, the engine of the economy and dynamics will be improved.
determine the fuel knock resistance is difficult, because the fuel knock resistance depends not only on the nature of the fuel, but also with the type of the engine, air-fuel ratio, cooling water temperature, intake air temperature, ignition timing, valve the timing and the like. 3, the octane number – reference:
In order to evaluate the fuelAnti-knock properties, generally use two methods: Method motor and research methods. Assessment work generally carried out in a specially designed variable compression ratio single cylinder engine.
Motor method as specified test conditions: inlet air temperature 149 ℃, cooling water temperature 100 ℃, the engine speed 900 r / min, the ignition advance angle on the dead point of the front 14deg; ~ 26deg ;. During the test, the measurement of fuel with the first work, the compression ratio is gradually changed until the date indicated on the knock meter standard knock intensity. Then, the compression ratio and other conditions remain unchanged, change jobs standard fuel. Reference fuel is high antiknock isooctane C8H18 (set as 100 octane) and easy knocking n-heptane (0 octane number which is set) mixture. Gradually changing the ratio of iso-octane and n-heptane, until the reference fuel knock intensity with the sample produced at the same time until the fuel phase. In this case the volume percentage of isooctane contained in the test fuel octane is the fuel standard. High octane fuel anti-knock like, on the contrary uprising of the poor.
For example: a fuel octane number of 80, which means that 20 percent of the antiknock fuel 80 containing isooctane and n-heptane mixture percentage of the same. This is the evaluation criteria for fuel antiknock.
The test method research method and the motor method, but only the different test conditions. Under conditions research method as follows: Inlet air temperature was 51.7 ℃, cooling water temperature of 100 ℃, the engine speed 600 r / min, the ignition advance angle of 13deg ;.
Since the conditions under demanding than MON study, the measured octane number and therefore relatively low. The same method to measure the motor fuel octane number is 85, corresponding to research octane number of 92; 90 is a motor method, research method 97. Now the gas station with a research octane number.
Generally, the way to increase gasoline octane plant has three: First, choose a good raw material and improving processing technology, for example by catalytic cracking, reforming and other secondary processing. Second, excellent antiknock transferred to high octane component of the product, e.g. isooctane, cumene, benzene and the like. Third, addition of antiknock agent.
2, with excessive oil standard oil drop
93 oil 90 oil expensive than 5 percentage, but the energy consumption is also small percentage of about 5, more than one hundred kilometers from the fuel amount of money is theoretically equal. But considering the 93 high compression ratio of the engine oil match with 90 oil when the secondary combustion and incomplete combustion phenomenon occurs, the extra 5 percentage -8 percentage of power loss, then consider increasing maintenance costs caused by vehicles, condition decline , reducing life expectancy and a series of consequences, lowering the cost of oil standard on the go.
Gasoline is highly volatile liquid, minus 30 degrees Celsius still combustible components evaporate when the low grade of gasoline, oil and gas will be compressed mixed before ignition in auto-ignition, ignition, spontaneous combustion of oil and gas has begun to turn to produce strong explosion, the combustion process was originally designed precisely out of control, some gasoline negative work done, in part because the combustion process is not synchronized with the piston stroke is not completely burned, causing the intake valve cylinder and a serious coke, increased fuel consumption, exhaust worse. When the car at high speed, the confusion of the combustion process will produce a continuous knocking, it will seriously damage the engine, causing the spark plug insulation break, electrode excessive burning, piston knock, stuck piston rings, valve ablation and other consequences. This “crazy” transmission mode, the drive to make their way to the car to work in the “high rock” state, the consequences can be imagined.
In recent years, 97 # gasoline began to appear widely in the domestic market. Some riders use of gasoline also fell into a misunderstanding, it is keen to use high-grade gasoline. Even some riders to grade gasoline as a fuel purity and quality standards. This is wrong. In fact, the level of gasoline label only indicates the size of the gasoline octane number, label must not be confused with the purity and quality. Insist on using 97 oil will be “ignition delay” phenomenon, that it is less than head down to the point of spontaneous combustion, the same phenomenon will appear incomplete combustion engine 93 oil.
3, domestic gasoline analysis
Status
From the current domestic fuel situation, a lot of 97 # gasoline is actually joined the exclusive 90 # gasoline octane, cumene, benzene and other additives and MTBEAntiknock comes not improve catalytic cracking, reforming and other secondary processing comes in the production process. 97 # high price of oil, profit, growth of the culture of some companies misuse additives. They stop at nothing to increase gasoline octane, completely ignoring the overall fuel usage in other areas, which resulted in a considerable part of 97 # gasoline is likely to cause engine deposits, corrosion and even parts of the case. Currently these phenomena appeared in some of the more high-end imported cars and POLO, Palio and Siena recently produced a manual Speedgear series of ultra-high compression ratio car body.
In contrast, domestic 90 # and 93 # gasoline processing technology is more to cross the border, and relatively low price, the profit is relatively not so rich, so there are fewer companies in 90 # and 93 # gasoline tinker .
On the other hand, due to the 90 # gasoline has been popular for many years, the vast majority of 90 # gasoline storage and transportation vehicles and gas stations fuel tanks are also used for many years, accumulated in the storage and transportation vehicles and gas stations more impurities in the fuel tank and more, which resulted in 90 # gasoline quality problems mainly in terms of impurities.
and 93 # gasoline is only the beginning of large scale more than two years, the majority of gas station # 93 cylinders also are relatively clean. Therefore, relatively speaking, 93 # gasoline is most reliable.
4 Comparative
In practice, using different riders No. 93 oil and 97 have different ideas and different versions: 1,93 sent
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octane 93 and 97 but is different, and fuel cleanliness does not matter, so 97 to 93 clean yet to be verified. Just a different fuel sources, inconsistent quality, the standard may reach only 93 of 97 in some gas stations. 97 to 93 do not necessarily make the car more fresh (even contrary), but because the quality of pure oil, oil consumption is likely declined. 2,97 send
:
97 oil antiknock better, with up operation of the engine softer, there was no feeling of power and fuel consumption. 97 one hundred kilometers than 93 provinces half the oil,Spread in looking back, 97 very good ah! Than meat appears to be 93 points, but the speed and lift ride feel good, nothing too much different, but it seems more than 93 of the 97 fuel-efficient. Gix cars: with 97, throttle, fuel injectors, oil, cylinders are clean, not much money, why not. 97 run up feeling a little softer, as acceleration and fuel consumption, and 93 almost. Purely personal feeling, but also very obvious difference. Feeling cool 97 than 93, but fuel consumption is higher than 1L 93, it may be a bad way after the switch 97. 3, centrist
:
have used for some time, feeling relatively strong and 93, but 97 seems to be able to run more than a few kilometers, I feel basically spend the same money is no big difference in the number of kilometers, will not save much money . GTX exchange 97 # 93 # oil from the oil do not feel anything. Plus 97 car lighter, fuel-efficient, but did not force speed. T cars to be higher than that (of course, not to have to use 97 high-oil) than I compress cars, CT car: the riders feel the car, the 97 to 93 speed slightly slower than that speed is not bad , it is a little delayed, unlike 93 so explosive and feel it up. Do not be too concerned about, but to add 97 oil must adhere to.
final recommendations as required by the user or user manual plus the corresponding fuel, or when maintenance problems manufacturers will therefore make things difficult! For high-end imported cars is recommended to use 97 # oil, for domestic mid-range cars, # 93 oil is sufficient. Be careful not to mix two types of fuel, no problem, plus exhausted oil back to the original number on it