Low octane or high octane?

Personally, I have never had such a question. And not at all because in the old days there was no choice. Then the people argued only about how best to switch from 93rd to 76th, which some kind people sold to other kind people for half the price, or even cheaper. Unfortunately, when you can fill a tank for a third, or even a quarter of the price of the state, all technical arguments cowardly go aside.

There were many solutions. Some then put an additional gasket in the cylinder head, others changed the spring rate of the distributor, others simply switched to late ignition, and the laziest did not change anything at all. But no one had any doubts that the Zhigul still runs much better on its native 93rd gasoline than on low-octane swill. However, what will you not go for for the sake of significant savings?

It is curious that today there are a lot of different gasolines, but the disputes have not stopped at all. The difference in the declared octane numbers between 92 and not so big, but the topic does not die. There are two reasons for praising the lower octane: the same desire to save money, as well as the fear of running into the shoddy quality of high-octane fuel. The latter circumstance was once generated by rumors that the 95th, they say, "bodyyat" more, but the 92nd is being done "right." Well, the first thing, about the cost, is still alive today - they say, we are not so rich ... and so on.

Generally speaking, the 92nd is no longer in Europe. But we are not Europe. And any search site still explodes with hundreds of publications in response to numbers 92 or 95. Well, I will express my personal opinion for the hundredth time. And I apologize to those who will not like it.

About. Especially I bring two photos from the gas station - one modern, the other six years ago. The cost of a liter of 92nd and 95th was, respectively, 33–70 and 36–70, and earlier - 24–70 and 26–70.

The absolute difference in the price of a liter was 2 rubles, became 3 (however, somewhere a little higher). And how much can you save on refueling with such a delta? One hundred rubles? Against the background of the current cost of the tank, this seems to me a frivolous cause for concern. And to those who are going to prove that even a hundred rubles is, they say, money, I sincerely advise. I promise you a much more significant financial gain - I wrote about this more than once. One and the same car can "eat" and 7 liters per hundred, and all 15.

Now on the technique. Any engine is calibrated for a certain grade of gasoline - this is a fact. And if the manufacturer wrote: they say, fill only the 95th, and - not a step to the side, then you need to listen to it. Even if you keep a combination of three fingers in your pocket. The car will run worse on low-octane gasoline (how could it be otherwise?), But that's not even the point. Imagine a bad case: there was a problem with the motor, and you came to the service. And there the funny guys first of all will take a sample of fuel from the tank. And if you find at least something "from the wrong opera", then you can forget about any. You need it?

Of course, this is an extreme case. Most modern engines designed for 95th gasoline will swallow 92nd without any problems. But I still urge you to fill only the gasoline that is indicated in the instructions for your car. If the spread is indicated, it is another matter: choose yourself. But if not, then do not carry out laboratory work on your own machine. Have pity on her. And myself at the same time.

By the way, all automakers have recently gone a little crazy, having unanimously started campaigning for the 98th gasoline. Say, do not fill in the low-octane 95th, no matter what is written in the instructions. Only the 98th in all cars, without exception! I have already spoken about this, and more than once, but the trend is clear: you give a high octane! And therefore I repeat once again: in the choice between 92 and 95, I am always over 95.

However, there are amusements in the Fatherland. An interesting observation was made recently by my former colleague Vadim Kryuchkov. He was interested in the question of what kind of fuel should be poured into VAZ cars - here it was. It turned out that there is no single approach at VAZ and Renault-Nissan: different grades of fuel are prescribed for the same engine installed on different models.

I am quoting Vadim. “For Vesta and XRAY with a VAZ-21129 engine, A-92 is allowed, and only A-95 is prescribed for similar engines on the Priora, Kalina and Grant under the VAZ-21127 index. Or, say, an eight-valve VAZ-11189 for Largus officially swallows the 92nd, and give the same Kalina VAZ-11186 only the 95th. " And here's another: “Why does the 16-valve K4M engine developed by the alliance under the hood of Lada Largus require the A-95, while in Almera, Logan and Sandero it can work on the A-91? Moreover, Renault even allows short-term operation on gasoline with an octane rating of 87 according to the research method. There is no such sort in Russia, but a low-quality 92nd can get into the tank, with which the motor will somehow cope. "

In short, the engineers did not agree with each other in which saint they should collectively believe. Earlier, at the same VAZ, a certain unity of views reigned: they say, 95 - that's all. The arguments are simple: at the same time, we promise you environmental friendliness plus economy plus throttle response, etc. There was also a spare argument: this is the so-called technological reserve, laid by the designer for all sorts of "if"! In other words, if somewhere, “not in our area,” as Comrade Saakhov said, you are still poured not 95, but something worse, then nothing will happen to your engine. But as soon as we resolve the 92nd, we will thereby take responsibility for some 87th ... And who needs it?

Today, it seems to me, it makes no sense to develop engines for the 92nd. If only because, as I already said, in Europe there are no more such numbers in everyday life. The lower modern limit is 95th. As for the modern and previously released cars, I will repeat once again: I am for the 95th.

Even if the automaker allows octane variation.

Which gasoline is better - 92 or 95?

Is it true that 92nd gasoline is better than 95th? Or is it worse? What should be poured into the tank in the end? And why do VAZ and Renault-Nissan recommend different grades of fuel for the same engines?

Which gasoline is better - 92 or 95?

Nikolay_1811

A week ago, he became the proud owner of Hitrila on the MR20DD engine and immediately the question arose about what kind of gasoline this newly-made miracle of technology eats. In the cabin, everyone shouts with one voice "only 95", but what a moral problem it turns out to be: I live in St. Petersburg, and here 95 is 92 + a bucket of chemistry the owner's manual reads "use UNLEADED gasoline with a research octane number (RON) of at least 91" and on the cap of the gas tank, where they usually write "95 !!!" nothing is written. With the MR20DE engine, it is more or less clear, distributed injection, ley what the soul asks for, but here it seems like direct, if I'm not mistaken. In short, the question is: who drives what gasoline and why?

I pour 92 gasoline, although we have good 95 in Kirishi, but I see no reason to overpay. It is written in the manual not lower than 91 so why bother to hammer in your head.

And the managers in the salons, alas, very often do not even know what is written in the instructions for the cars for sale. For example, I was assured that there is no rear camera washer on the T32 (LE +) and that the hatch opens only in one position.

18.6.2015, 10:06

Lew 92 Kirishi. Mileage 157,000 km no questions asked.

28.6.2015, 23:54

With the MR20DE engine, it is more or less clear, distributed injection, ley what the soul asks, but here it seems like direct, if I'm not mistaken. In short, the question is: who drives what gasoline and why?

Well, MR20DD is also a low-powered engine, like DE.
I'll look for info. Before buying X, I was looking specifically for DE info. There is a lot of information on the network. For example, on what models does it still stand and what about gasoline for this model is written on American sites.
And what do these engines drive in Japan. Japan has 91st gasoline. It is called "regular".
I had a DE - 70,000 a month ago, there are still some candles (they are off the assembly line).

And the managers in the salons, alas, very often do not even know what is written in the instructions for the cars for sale.

And about gasoline once in a Toyota meGer annealed. When asked why OD claims that only the 95th is needed, although in the USA these motors work WITHOUT PROBLEMS on the 92nd. He issued: And in the states the octane number is 92, as we have 95. I could not restrain myself - he laughed long and loudly.

29.6.2015, 10:29

And about gasoline once in a Toyota meGer annealed. When asked why OD claims that only the 95th is needed, although in the USA these motors work WITHOUT PROBLEMS on the 92nd. He issued: And in the states the octane number is 92, as we have 95. I could not restrain myself - he laughed long and loudly.

29.6.2015, 13:44

It is a pity, of course, that 80 and 76 were removed from gas stations, so it could have been used to pour it, laughing in the face of all sorts of managers

To be honest, I did not look at gas stations in St. Petersburg, but AI-80 is so freely and officially sold here.

29.6.2015, 15:55

29.6.2015, 17:27

The instructions for T31 say that gasoline must have an octane rating of at least 91, but the car provides its maximum dynamic characteristics only on gasoline 95. Something like this. You can see a more precise wording.

29.6.2015, 19:00

This is true. But I still have some doubts that the instruction was written taking into account the Russian characteristics of octane.

The instruction is written in Russian. Moreover, the instruction is official. There seems to be no reason not to believe.

29.6.2015, 19:16

Stitch,
someone believes the instructions,
someone information that if the compression ratio is less than 10, then the 92nd doctor himself prescribed,
someone measured that the flow rate is the same, but the dynamics are the same.

The X engine is not particularly capricious, that it is poured into the tank, then it digests.
That is why half of them drive 92nd, the other half drive 95.
And everyone, in their own way, is right.

29.6.2015, 23:11

The manager was wrong, of course. In the USA the term "octane index" is used. It is the arithmetic average between the research octane (RON) and motor (MON) methods.
If the instruction says "octane index 91" then even our 95th (RON) is questionable, since its index is less than 91

Well, if you really think so, then not the "octane index", but the "anti-knock index" or something like that - I don't remember exactly, but it starts exactly with the letter "A".
Yes, there is such a concept in the states. But it was the octane number that was discussed with the Menager. This time.
Secondly: In Japan, the octane number is indicated by the research method (like ours) - I know for sure. And there the MR20DE engine is excellent and does not contradict the instructions, it works on the 91st gasoline - "Regular".
Thirdly: There is also information about gasoline on the fuel filler flap (applied at the factory). So on a Japanese car with an MR20DE engine it is written simply: only unleaded gasoline.

29.6.2015, 23:17

The manager tried to explain in simple language, for dummies. But they still did not understand him. It is a pity, of course, that 80 and 76 were removed from gas stations, so it could have been used to pour it, laughing in the face of all sorts of managers

MeneGer (pay attention to the spelling of the word) tried to answer the question of the answer to which he does not know. This time.
MeneGer and manager are two different concepts for me. The manager is quite an adequate specialist. And meGer is a dunno with a show-off. Moreover, to admit that he does not know something, it seems that religion does not allow him, and that is nonsense. There are plenty of them not only in car dealerships.
And the third, which follows from the second, is that it is a sin not to laugh at meGer.

what if the compression ratio is less than 10,

Actually, the MR20DE engine has a compression ratio of 10.5. And DD has a little more (the head is different).
And roughly speaking, an engine with a compression ratio of up to 11 is considered to be low-powered.

29.6.2015, 23:24

Engine 2 liters, pour 92 already 200 thousand! The flight is normal! I have never cleaned the throttle valve !! Catalyst error has been lit for 2 years

I remembered an interesting point regarding Japanese engines:
There was no 95 gasoline in Japan in the last century. I rummaged through the net. Found Japanese gasoline standards. And now he is gone.
There is no 95th gasoline in Japan, like there is no 92nd in Europe. There is the 91st, there is the 98th, and the 92nd is not. How.
Those. a Japanese engine, in principle, cannot be designed to run on 95th gasoline. Or at 91st and above or at least 98th.
And here we are arguing 92nd or 95th. And you have to argue 92nd or 98th.

I do not quite agree that when a car receives accreditation and a certificate (in the Russian Federation gost R or a certificate of conformity), then it is tested for the type of fuel that is in the country, therefore it is not entirely correct to compare the fuel of the two countries

I don't quite agree

To agree with the facts or not is everyone's personal business. But the facts from the fact that someone does not agree with them do not cease to be facts.

I just remembered at my leisure at the hotel that when I bought more than one car in Japan in the mid-90s, there was no 95th gasoline, as such. And now he is gone, as it turned out.

P.S. And I did not quite understand your phrase. Explain. We have the 92nd and 95th and 98th.
And the states also have 92nd and 95th and 98th .. But if you look at the OD website in the states, we will see that Regular gasoline with an octane rating of 91-92 is recommended (according to the generally accepted research method) and with AKI 86-87. And this is also a fact.

P.S. When I asked MeneGera in Toyota, I was interested in the official motivation of the Russian representative office. But meGer suffered nonsense. Although I believe that OA should know the official motivation.

14.7.2015, 15:50

Nikolay_1811

O! Fine. I'll get my new one - I'll start saving on benzus :-)

It's a little sleepy, the compression ratio is still 11.2, this was not done for the 92nd engine. Although once a full tank 92 was filled - there is no difference, except for the consumption, but the question is what will happen if you constantly ride on it ...

Nikolay_1811

Hmm .... and where in the Russian manual it says "not lower than 91" ???? I have written "... 95" (Dviglo 2.5 l). Esseno 92 filled in and a full tank and half. Okay to experiment. I did not notice a difference in dynamics, but before that, the established average consumption at the 92nd crawled up somewhere by a liter.
On my wife's 2-liter, the difference is more noticeable. He is not very smart anyway after you change from 2.5, and on 92 it seems that he does not go at all. Although he is a purebred right-hand drive Jap, designed for the 91st Benzus.

So in the QR25DE engine with a compression ratio of 9.5 (if I'm not mistaken) 92 is just right

It's a little sleepy, the compression ratio is still 11.2, this was not done for the 92nd engine.

Well, yes, the compression ratio is higher than that of the DE, and the injection is direct, not distributed. Under what gasoline 91st or 98th this engine made it difficult to say. Where to look for information, I expressed my thoughts.
But it was definitely not made under the 95th. There is no 95th in Japan.
And then - Japan. And the Japanese manage to make a diesel engine under Euro-6 standards without a Common Rail system (with a block injection pump) and without exhaust gas recirculation.

Theoretically, the correct answer to the question about the preferred octane number for a particular engine is given by the instruction manual of the machine. However, sometimes this information can lead to a dead end. Renault-Nissan vehicles are one such example. Often, for the same engine installed on different cars, gasoline with a different octane number is recommended. What's the matter?

For example, the alliance's K4M engine is used in Almera, Logan, Sandero and Largus. At the same time, for the first three models, the manufacturer allows the use of AI-92, and for the latter, only AI-95 is prescribed. Let's say more: the instructions for Renault indicate that the engine can run on 87th gasoline, but only for a short period of time. This sort, of course, is not sold in Russia, but it will enable the engine to "digest" the bad 92nd.

In fact, the requirement for using the AI-95 is clear. It has been scientifically proven that high-octane fuel allows you to achieve the best performance, efficiency and environmental friendliness. Moreover, it is a kind of safety net against the use of low-quality fuel. If you refuel at a dubious gas station from a pistol marked "95", then 92 gasoline may get into the tank. And the motor will handle it. But what will be in the tank if you pay for AI-92 gasoline? It is quite possible that the 80th or even the 76th. But this will already cause certain problems.

The absurdity of the situation is added by the following observation: more expensive cars, including many Nissan models, are allowed 92 gasoline, but only AI-95 is recommended for budget models.

What to refuel

Excellent, we have decided on the gas station. Now let's choose the brand of gasoline to use. Most gas stations have three options - AI-92, 95 and 98.

There is an opinion that it is best to refuel the 92nd. Allegedly, it contains fewer additives, impurities, so the fuel is cleaner and does not form carbon deposits on the candles. The 95 gasoline alternative is dismissed with arguments that it will redden the candles and cause other unpleasant consequences.

This might be true, if not for one important fact. Numerous measurements of the octane number of fuel at Russian gas stations revealed that, under the guise of 92nd, they often sell, attention, 80th gasoline. And such a picture is observed in all regions of the country, even in those where million-plus cities are located. It turns out that the declared brand of gasoline does not always correspond to the real one.

Now let's go to the fuel filler flap and open it. If the manufacturer indicates that you need to fill in AI-95, you should not risk it - it's better to just follow the instructions. Trying to save money on fuel can lead to costly repairs, even though the designers have made plans to run on a different fuel. Do you remember that a pistol marked "92" most often pours gasoline with a lower octane number?

Those who have it written under the hatch that it is possible to refuel the 92nd and 95th will have to decide. If you are sure of the quality of fuel at the gas station of your choice, feel free to follow this recommendation. At the same time, if you use AI-95 gasoline, nothing bad will happen. On the contrary, you will notice a decrease in consumption, an increase in the dynamic characteristics of the engine, and a decrease in wear of parts. If your mileage is 12 thousand km per year, then for 365 days of operation on fuel with an increased octane number you will overpay about 3000 rubles.

Many people had a question: "Maybe use AI-98 gasoline to make the car run even better?" The answer is no. Switching to such fuels will do more harm than good. The fact is that such gasoline is used in sports and forced engines with a high compression ratio. This is not the right choice for production Nissan vehicles.

However, don't forget about the AI-98. If you suddenly come across low-quality gasoline that killed the dynamics of the car, fill the tank with 5-10 liters of the 98th. The octane number will level off and you will be able to get to the service station on your own, where they will carry out diagnostics and the necessary maintenance of the fuel system.