do you use 87 octane in your honda ex civic.

[captain2]

do you use 87 octane in your honda ex civic manual says 87 octane and salesman 87 to 89 octane but no higher. know the si wants premium

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[saz468]

I’ve been running 93 (shell) in my car since I bought it for two years now no problems
I’m old fashion I’ve been told turbos should run with a higher octane this is my opinion. you can run 87 on a stock 1.5 turbo

 

[BriteBlue]

The manual says 87 octane so that's what I use.

 

[gtman]

When I see these gas brand, gas octane or gas mileage topics, it always feels like deja vu all over again.

Am I the only one? Maybe we need a special "Gas, Mileage and Related Topics" forum here at CivicX.

 

[tinyman392]

do you use 87 octane in your honda ex civic manual says 87 octane and salesman 87 to 89 octane but no higher. know the si wants premium

There is no issue running higher than required, but you won't get much gains out of it. At least you won't get anything to offset the price of the higher octane.

 

[BriteBlue]

At Costco by me the difference between 87 & 93 octane is $0.53 per gallon. They do not have a mid-grade and no one has 91 octane. All premium by me is 93 octane. At shell the difference between 87 & 93 is $0.85 and by Mobil it's $0.82 per GasBuddy. That's a big price increase, especially to put in an economy car made for 87 octane.

 

[FC3L15B7]

do you use 87 octane in your honda ex civic manual says 87 octane and salesman 87 to 89 octane but no higher. know the si wants premium

The issue with using a higher octane level than specified is volatility, emissions and your catalytic converter. Higher octane gasoline resists igniting, so if you're not burning the fuel efficiently, you can have misfiring in cold weather, poor fuel economy, lower power output and the additional NOx from rich ignition can ruin your catalytic converter - not to mention foul up your O2 sensors.

The only time you should increase the octane level is in the summer if your engine is pinging when hot. Otherwise, use what is recommended by the manufacture.

 

[brienp]

I'm just commenting on here so the system will notify me of future comments. That way I can watch all the uninformed people discuss their opinions as if they were fact, because someone, at some point in time told them 93 is better than 91 and 91 is better than 87. And then I smile to my self knowing there is a high probability they hold in their hand a device that allows them access to the entire wealth of human knowledge, but rather than simply looking up the differences and purposes of 87, 91, 93, 97 and 100+ they instead post their "fact" opinions. Carry on. This will be a great diversion during my lunch break.

 

[Lola]

87......and if they had 85 octane I’d probably use that!

 

[NonyaBisness]

the cheap one because that is what the car was DESIGNED FOR!!!!!!!!!!!!!!!!!!!! Don't be an idiot and pay 50 cents more per gallon for NO REASON, damn, it was a hard enough argument when it was 20 cents more per gallon, 50 cents more is just insanity, you ONLY NEED PREMIUM IF YOUR CAR SAYS IT REQUIRES IT!!!!!!!!!

 

[NazTehRpR]

I use mid-grade since I drive in S mode on the daily so I’m always in higher revs plus I enjoy playing with the paddle shifters. Otherwise I only use D + Eco when going to work since it’s a 40 minute commute on the freeway. But then I go back to using S going on the way back home on the backroads.

 

[Gruber]

The issue with using a higher octane level than specified is volatility, emissions and your catalytic converter. Higher octane gasoline resists igniting, so if you're not burning the fuel efficiently, you can have misfiring in cold weather, poor fuel economy, lower power output and the additional NOx from rich ignition can ruin your catalytic converter - not to mention foul up your O2 sensors.

The only time you should increase the octane level is in the summer if your engine is pinging when hot. Otherwise, use what is recommended by the manufacture.

Totally false, in other words, BS. You don't understand fuel.

You can pour high octane gasoline in any gasoline engine anytime you wish, if you can afford it, without any ill effect whatsoever. High octane will not help most cars at all, it will help some cars a bit, and it will make a big difference for those cars that are designed/tuned for high octane. Volatility has nothing to do with octane. Some very volatile hydrocarbons have a very low octane number. Higher octane fuel resists autoignition, in particular under pressure, it does not resist ignition with a spark. Flash point and autoignition temperature are different things. You must be confused by diesel fuel/engines.

 

[FC3L15B7]

Totally false, in other words, BS. You don't understand fuel.

Volatility has nothing to do with octane. Some very volatile hydrocarbons have a very low octane number.

I didn't say higher octane gasoline was more volatile, but octane has everything to do with volatility.

You can pour high octane gasoline in any gasoline engine anytime you wish, if you can afford it, without any ill effect whatsoever.

Higher octane fuel resists autoignition, in particular under pressure, it does not resist ignition with a spark.

The presence of spark does not guarantee ignition. The voltage - or energy of that spark - has to meet the minimum ignition energy or MIE. I suppose you're about to get a lesson in ignition systems and spark plugs.

An engine designed for lower octane, higher volatility gasoline may have spark plugs with narrow spark plug gaps because that's the gap that is most efficient for that engine. Those narrow gaps need less voltage than a spark jumping a larger gap, which you typically would have in higher-performance engines using premium gas. In a "premium engine", you need a higher energy charge to get the spark to jump a larger gap and its voltage is high enough for MIE when using higher octane gasoline to not just ignite the fuel, but burn it as completely as possible while resisting preignition. The more complete the burn, the higher the power output, higher fuel mileage, lower emissions, less NOx for your catalytic converter and less money. Further to the point, if the engine is designed to use lower octane, that is the grade that should have the most complete combustion (aka higher the power output, higher fuel mileage, lower emissions, less NOx). Using higher octane gas when it's not applicable can have the opposite effect.

For example: If you compare 87 octane and 91 octane gasolines in an engine that is supposed to be using a lower octane and has narrow spark plug gaps because that's its most efficient gap for that engine design and appropriate grade of fuel you may not get ignition or can have incomplete combustion from the higher octane, lower volatility gasoline when it's cold. In addition to the likelihood of lower voltage sparks across a narrow plug gap, the gasoline doesn't evaporate as quickly in the cold, exacerbating the issue.

Higher octane fuel resists autoignition, in particular under pressure, it does not resist ignition with a spark. Flash point and autoignition temperature are different things. You must be confused by diesel fuel/engines.

When it's hot, it's not likely to affect it because even the higher octane fuel is evaporating quickly and the combination of heat and compression is pushing the limits of autoignition you're so fond of you had to use bold type.

Preignition is a type of autoignition like thumbs are fingers but fingers are not thumbs. Preignition is the lowest temperature of ignition without an external ignition source or flame before ignition is supposed to occur and Autoignition is the lowest temperature of ignition without an external ignition source or flame at the time ignition is supposed to occur. Preignition is what high octane, lower volatility gasoline resists. Preignition is due to higher heat levels, which is why you may get engine knock in the summer while using the recommended fuel grade and can go up in fuel grades to resist preignition and reduce engine knock. Autoignition is what you get from compressing diesel fuel and doesn't belong here because we're talking about gasoline internal combustion engines that have external ignition source, even though some diesels do. It doesn't matter here. I hope you've learned something.

 

[Flash5]

The only reason I would PERSONALLY run premium gas in a car that was designed for regular gas is if it was super old with a lot of carbon buildup causing knock because of this OR if here and there I wanted the benefits of all the additional detergents in premium gas (if it is to be believed). There is literally NO performance benefits to using 91/93 or higher octane on a car that only requires 87 unless it is properly tuned for premium gas. It is funny to me that these threads on fuel octane occur on every forum site lol. On Club Lexus people want to insist that it's perfectly fine to run 87 in our 3rd Gen IS which is tuned from the factory for minimum 91 octane because the computers will pull the timing to prevent issues. While that MAY be true, why would you want your car to compensate all the time? I don't understand why people can't just run what the owner's manual recommends which is based off of what the engineers etc designed it around.

 

[integraboi]

I made the mistake of putting 89 instead of 87 into mine...

It made a $10 difference, never again lol.

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