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26 votes

Wrong octane fuel

It's not a problem mixing them. Just start using 95 if that is what the engine calls for. You'll not create any issues doing so. Modern day engines have sensors which can adjust for the fuel. If ...
21 votes
Accepted

Should I use gasoline 87, 89 or 93 on 2016 RAV4 SE

Realistically, if the manual and the manufacturer are stating you should use 87 octane, that's really what you should use. If you purchase more expensive 89, 91, or 93, you are just wasting money. The ...
11 votes

Wrong octane fuel

Presumably since you say "92 octane gas" you are not in Europe. The whole topic is a mess, because there are different scales for measuring "octane". The most common scale world-wide is RON, but ...
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7 votes
Accepted

Is it fine to use higher octane gasoline than what is recommended on the fuel cap sticker

It means "at least". You will not cause any damage by using the higher octane fuel. The reason for the RON 95 rating in the first place, this is the lowest octane rating you can run before you might ...
7 votes

Can I use lower octane fuel at high elevation?

You have nothing to lose on a modern engine (except power) Any engine with a knock sensor and computer-controlled ignition timing (e.g. modern fuel-injected designs) should be able to alter ignition ...
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6 votes

Lexus RX200t octane

If the manual says that 95 octane is suitable then the car will be fine with 95 octane. 98 will only yield appreciable performance gains if the ignition advance is being actively limited by engine ...
  • 39k
6 votes
Accepted

Will 93 octane fuel burn completely in an 87 octane engine?

"Higher octane" only means more knock-resistant. It does not mean "harder-to-ignite" or "hotter burning." A gasoline engine will not perform worse in any way on higher-octane gasoline. The higher-...
  • 1,189
6 votes

How can my car run on 85 octane but be recommended to run on 91?

In current fuel injected vehicles, the computer (ECU) adjusts for it. There are sensors in your engine called "knock sensors". When the sensors start picking up a knock, it will pull timing. Usually, ...
5 votes

Switching to a higher octane

Mixing 95 octane gasoline with 92 is perfectly fine. In fact, this is what many gas stations do in order to offer their mid-grade product. For example, many gas stations in the United States offer 87, ...
  • 51
5 votes
Accepted

Premium vs. regular in medium compression engines

There is no such thing as an octane sensor. Octane is analyzed in two ways. Analysis of the chemical composition, they call this Research. They place the fuel into a test engine and run it until it ...
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5 votes
Accepted

Lexus RX200t octane

As Zaid said, if the manual says 95, use 95. Simple as that. Actually, using a higher octane rating is not ideal, whatever it may seem. From whatcouldbegreener.com: What will happen if I use ...
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5 votes
Accepted

Octane number definition differences in different countries

There are different ways to measure the octane number of a fuel. Europe uses the RON method. Research Octane Number (RON) The most common type of octane rating worldwide is the Research Octane Number ...
  • 4,412
5 votes

Wrong octane fuel

A modern car (say, post-1995) will run on lower octane gasoline with reduced performance (power, economy) and no other issues. Older cars did a lot of nasty things ranging from occasional "pinging" ...
  • 1,962
5 votes

Can I mix RON 97 fuel with RON 95 fuel in my car?

Absolutely you can mix different octanes of petrol (gasoline) in your car, it won't hurt your car and you may get better performance with a more expensive fuel. Premium fuels are generally better ...
  • 14.9k
4 votes

Should I use gasoline 87, 89 or 93 on 2016 RAV4 SE

The acid test is if you try a lower octane fuel, if you hear any "knocking" sounds under hard acceleration (perhaps up a hill), then you definitely need a higher octane rating. As Paulster2 mentions, ...
4 votes

Is it a good idea to top off the gasoline with higher octane fuel in a specific case?

In the case of topping off, it would make absolutely no difference other than costing you more at the pump. Octane is a rating which would indicate how hard it is for the fuel to burn. The higher the ...
4 votes

Can mixing octanes cause the check engine light to come on?

Using a higher octane fuel should not have caused the SES light to turn on. The only fill-up-related thing I can think of which would cause the SES to turn on is if there is a bad batch of fuel (...
  • 39k
3 votes

What grade of fuel should I use for my car?

Generally, you're best off using the fuel recommended by the manufacturer. Octane rating is a measure of how resistant the fuel is to ignition. The higher the octane, the harder the fuel is to ignite....
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3 votes

Gasoline grade manufacturer recommends vs what was used during testing

This claim is my opinion. I have no facts to back the claim. This could even be urban legend I've read a plethora of articles recently, due to this question, regarding this subject. It seems to be ...
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3 votes
Accepted

Switching to a higher octane

To answer your question directly, adding the 95 to the 92 in your tank will not cause any real problems, in the short term. Once you have used the tank full you can carry on filling up with the ...
3 votes
Accepted

How often does my engine check fuel octane?

The ECU(or at least the better ones) can indeed actively 'search' for the point of pinging as you said. The pinging sensor listens to the combustion, based on that the ECU determines how close it is ...
  • 2,929
3 votes

Does petrol gradually get a higher octane rating with evaporation over time?

Addressing the question from the point of view of a chemist: this sounds highly implausible. Evaporative distillation is not terribly efficient to begin with, even with very different chemicals. I.e....
  • 1,189
3 votes
Accepted

Recommended fuel for Honda Fit Sport 2008

You can take a loot at this Q&A about the octane. For your car, I'd say go with whatever the manufacturer says. They say "87+" then 88 will run fine. There are factors other than the octane rating ...
3 votes

Recommended fuel for Honda Fit Sport 2008

Which country do you live in? The gas station should specify whether they are quoting RON or R+M octane. And which market was the car originally sold for? For example: In the U.S., octane is ...
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2 votes
Accepted

Changing spark timing to use a lower octane fuel?

Could the increase in the electrode gap in the spark plug cause wear on the ignition coil/charge distributor? Increasing the gap on spark plugs does cause wear on the all the parts you mention. I ...
2 votes

Changing spark timing to use a lower octane fuel?

I am not sure about increasing the electrode gap but the rest I can answer. Retarding the timing should not cause any damage to the internals of the engine. it is basically making the spark happen ...
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2 votes

Should I use gasoline 87, 89 or 93 on 2016 RAV4 SE

87 will work, 89 is optimal, 93 will also work but uses a bit more (will start to run leaner but the computer easily compensates but using more fuel) 87 better for winter (no difference over 89), 89 ...
2 votes
Accepted

Can mixing octanes cause the check engine light to come on?

Mixing octanes in an upward-direction is fine. But, not completely tightening the gas cap could cause that. If you want to know exactly why the CEL came on, just take the vehicle to a retail car-...
2 votes

Difference between high octane and low octane?

Here's the deal : higher octane means less volatility, and this is meant for engines with higher compression so that the fuel doesn't ignite too early in the cycle . Lower octane fuel is more ...
2 votes

How often does my engine check fuel octane?

The only sensors used to determine fuel quality are the knock and mixture (Oxygen) sensors. The adjustments are continuous whenever the engine is running. The vehicles I have experience with, this ...
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