Who Uses 93 Octane?

I have an EXT over 23,000 miles, and always put in 87. It runs fine. I tried 93 a couple times, didn't notice any difference.

Civics4Ever said:

I have an EXT over 23,000 miles, and always put in 87. It runs fine. I tried 93 a couple times, didn't notice any difference.

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I didn't notice any difference either with the 93. They just threw me by adding that part about transmissions with sport mode require 91. I wasn't sure if they meant sport models, or transmissions that have the sport mode which my ex-t does have. If I can find it again ,ill post it.

Ok, I found it. Now my car has sport mode on the shift lever, but no button so I don't know which they are referring to.

If you have a sedan or coupe, Sport mode is if you have the Sport button (in place of the Econ button) - in other words, an Si. Check the inside of your fuel door. It should say there whether regular unleaded or premium unleaded is recommended.

To beat a dead horse: The only Civics that are premium recommended are Si (sedan and coupe), Sport (hatch), Sport Touring (hatch), Type R. All others only need regular 87 octane.

Octane is to prevent knock. Higher octane = less pre-ignition likely (knock). Knock is most likely when hot engine and outside air temps and/or under heavy load.
Some cars are tuned to take advantage and make more power from higher octane. As you can see in post #33 the owners manual says 87 or above will work.

Honda apparently tunes 'sport' mode cars for 91 to make more power and possibly better fuel economy.

Putting in higher quality fuel is strongly recommended. I'd put 87 Shell or 87 Chevron before I put in cheap premium.

For those who don't know, gas stations have two tanks. Fuel is delivered to the 87 (or 86 in certain parts of the the USA) and Premium 91/93. Mid grade is just a half and half blend.

Australia and many other parts of the world do not use the R+M/2 method so you might see a 98 octane. That's more like 91/93 in the USA.

I miss the old days when Premium was 20 cents more than regular. Some parts of the USA still are. Around me, it's 40-90 cents per gallon more. I drive 30-40k miles per year. It can add up to real money.

Chris

TurnOne said:

Octane is to prevent knock. Higher octane = less pre-ignition likely (knock). Knock is most likely when hot engine and outside air temps and/or under heavy load.
Some cars are tuned to take advantage and make more power from higher octane. As you can see in post #33 the owners manual says 87 or above will work.

Honda apparently tunes 'sport' mode cars for 91 to make more power and possibly better fuel economy.

Putting in higher quality fuel is strongly recommended. I'd put 87 Shell or 87 Chevron before I put in cheap premium.

For those who don't know, gas stations have two tanks. Fuel is delivered to the 87 (or 86 in certain parts of the the USA) and Premium 91/93. Mid grade is just a half and half blend.

Australia and many other parts of the world do not use the R+M/2 method so you might see a 98 octane. That's more like 91/93 in the USA.

I miss the old days when Premium was 20 cents more than regular. Some parts of the USA still are. Around me, it's 40-90 cents per gallon more. I drive 30-40k miles per year. It can add up to real money.

Chris

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Great post.

I hear ya on the price of 93. I have to run 93 in my WRX and it hurts every time. I barely drive that thing now because it costs me more than twice as much in fuel to drive compared to my Civic.

That depends on where you drive...so I'm told. Here in Colorado our dealer insists we us 85. Anything higher could cause pinging, timing issues, and poor gas mileage, etc. I've always used 85 in my vehicles including my 17' Civic. No issues.

17Civ

At altitude 85 or 86 is the flat-lander version of 87. It's fine for your vehicle and usually only available at higher elevations. But, your dealer is all wet concerning his reasons - higher octane won't hurt your car only your wallet.

Rickmeister 48 said:

I recently downloaded an updated manual for my 2017 ex-t, it now states that transmissions with the sport mode should run 91 to prevent engine knock and reduce performance.
I could swear it didn't say anything like that when i got it, and I've run 87 with no issues. So I go to put in 91 and all they have is 87 ,89, and 93. It cost me 31.00 to fill up when I used to be able to fill up for about 23.00 I can't afford to put 93 in it.

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Im with you where do you even buy 91 octane gas I haven't seen any of that where I am from. Is there a specific branch of stations that will definitely have it?

Where you have the Green Econ button my Si has the Sport button.
Pretty sure they are referring to the Si and Type R not the EX-T.

jmr said:

Where you have the Green Econ button my Si has the Sport button.
Pretty sure they are referring to the Si and Type R not the EX-T.

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Yep, they kinda cleared it up in another comment. I am assuming you are talking about the post a few pages back. Your sport button is an econ button on other models.

darkness975 said:

Evening (or morning) all,

I have always used 93 Octane fuel in my cars. The owner's manuals say 87 or higher. I always figured it was better for the car to run cleaner fuel.

Most people I tell this to look at me like I have three heads and say "zomg why you paying so much extra money gas is expensive enough just use regular 87 it'll be fine" etc.

I have the EX-T. Am I wrong for assuming 93 Octane is better for the car?
Who else here uses it, even though they don't TECHNICALLY have to?

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octane = resistance to detonation. This is important in gasoline internal combustion engines because the compression can pre-detonate the gas/air mixture in the cylinder. I use 91 or 94 when available because in the manual for my car ( wrx 2015 ) it says use 91 unless 94 is available. The only reason I do it is because the wrx engine is high compression and it 'needs' it to run well. If you car manual says to use 87 or better it means if there is only 89 or 91 available it's a ok to use it but really you should be using 87 octane. There is 0(zero) advantage in using the higher grade for a low combustion engine where the only potential exception is if a certain gas seller specifically has bad/old fuel. You also wont get better mileage or a cleaner burn ( asside from the potential aditives in the fuel, go with big named petrol sellers if possible 'shell' 'petro can' 'ultramar' instead of 'back road joe's gas station' ).

Why do you get mixed messages: gas companies have been spewing lies about these 'premium' gasolines being required in 'every day engines' for years ( google here will work wonders ). They aren't... why? it costs more simple as that.

( first page clearly states regular gas. https://www.honda.ca/Content/honda..../ModelPage_Downloads/Civic_Sedan_specs_EN.pdf )

( the only reason I use 91 + https://www.vehiclehistory.com/vehicle-gas-type-specifications/subaru/wrx/2017 )

p.s octane doesn't stop at 94, it goes all the way to race fuel

p. p. s: cbc made a story on it

"premium" is a misnomer. 93 octane is not better or higher quality than regular. By government regulation all gas sold in the U.S. has to have the required additives for cleanliness and engine protection. All octane does is delay detonation in the combustion chamber. This is required for certain high compression engines. Nothing to do with quality. If your engine doesn't require premium gas in order to run right you're wasting your money, pure and simple. Those who think their engine runs better on premium are experiencing the placebo effect.

David Harper said:

"premium" is a misnomer. 93 octane is not better or higher quality than regular. By government regulation all gas sold in the U.S. has to have the required additives for cleanliness and engine protection. All octane does is delay detonation in the combustion chamber. This is required for certain high compression engines. Nothing to do with quality. If your engine doesn't require premium gas in order to run right you're wasting your money, pure and simple. Those who think their engine runs better on premium are experiencing the placebo effect.

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True, but these are Turbo engines. They will always do better on higher octane period.