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Author Topic: Using Recommended 93 Gas Back to Topics
Firedawg99

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Virginia

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Message Posted: Feb 7, 2013 1:29:56 PM

If the owner's manual recommends/suggest that a high end brand car only use 93 octane, would putting 87 REALLY damage the engine and parts?

Also is it more recommeneded you only use 87 as emergency gas and run it out before putting 93 back in?
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geobmw
Champion Author Miami

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Message Posted: Jul 1, 2013 11:01:32 PM

I use it. Recomended by manufaturer
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WEPSMAN
Champion Author South Dakota

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Message Posted: Jul 1, 2013 10:15:19 PM

Your car will not run at peak performance without using what is recommended.
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bluenvoy
Champion Author Nashville

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Message Posted: Jul 1, 2013 10:18:47 AM

If the owners manual says 93 octane the put 93 octane in it.
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Titanic1985
Champion Author South Carolina

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Message Posted: Jul 1, 2013 9:45:47 AM

Good Morning Firedawg99,

Thank you for providing the exact wording of your Owner's Manual. You said it reads, "After looking at the manual, it states that anything other than 93 will cause an audible knocking and acceleration will be greatly decreased."

JimBlake56 has drawn a very logical conclusion, BUT you car's Owner's Manual uses the key word "will" to indicate that audible knocking and decreased acceleration will occur. Remember, this is not a sales promotion for Premium, but rather a mandate from the engineers who designed the engine. Severe or prolonged knocking will most certainly damage an engine over time.

You haven't mentioned your vehicle's year, make, model or engine, so the best I can lead you to is this link which will show you a great deal of information about your vehicle. I very much doubt that it will differ from your Owner's Manual:

US Department of Energy

My advice based on your new information is to use 93 Octane Premium (91 Octane in my locale). You really don't want to damage the engine!

I hope this link helps you. There is a wealth of information there.

Best Wishes :-). MGY

Just to clarify the issue of engine knock, here is another link:

Three Causes of Engine Knock

The first item on the list is fuel with too low of an Octane rating (e.g. Anti-Knock Index).

[Edited by: Titanic1985 at 7/1/2013 9:47:02 AM EST]
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2Tall
Champion Author Maryland

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Message Posted: Jul 1, 2013 8:55:14 AM

no brainer...
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Z03
Sophomore Author New York

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Message Posted: Apr 3, 2013 2:08:29 AM

Use 93 if it says 93
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JimBlake56
Veteran Author Akron

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Message Posted: Apr 2, 2013 12:43:34 PM

I'm surprised it would say "audible knocking" etc. Modern engine controls can handle that pretty routinely. If they can put a knock sensor & the software to pull back spark timing on a base-model Civic or Hyundai, then why would a "high-end" car be any worse?

The question/answer is beginning to get pretty specific, so we can decide whether we're talking in generalities vs. specific to a certain model & year of car.
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gascomber
Veteran Author Durham

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Message Posted: Apr 1, 2013 9:20:04 PM

idk but i wouldn't try it
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Titanic1985
Champion Author South Carolina

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Message Posted: Apr 1, 2013 9:16:32 PM

Hello,

I sent Firedawg99 a very detailed explanation of Octane ratings and how they relate to engine timing, both pre-detonation and post-detonation. In it I referenced modern engines to those of bygone years and how with computer driven engines, there is only a limited amount of adjustment possible and virtually none by a mechanic (save "performance" chips which may void warranties). I also recommended searching the Internet for various topics to better understand the answer to his question.

As always, thank you GBs for your feedback. I too learned a few new things :-). MGY

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Firedawg99
Sophomore Author Virginia

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Message Posted: Apr 1, 2013 1:07:34 PM

After looking at the manual, it states that anything other than 93 will cause an audible knocking and acceleration will be greatly decreased.
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Firedawg99
Sophomore Author Virginia

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Message Posted: Mar 3, 2013 12:39:30 AM

titanic- thanks for the info. I will have to look it up for the "exact" wording and get back with you all. Nice to see folks really care and trying to help out.
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DasAuto92
Champion Author Montreal

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Message Posted: Feb 16, 2013 10:55:30 AM

Running the recommended octane delivers the best power and gas mileage. Saving a couple cents on gas when filling up doesn't equate to the loss of power and mpg. Running a higher octane than recommended usually does nothing for an engine since the ECU isn't mapped for it.

Bottom line:If your 2nd most important purchase in life besides a home needs to be fed fillet mignan, don't feed it regular hamburger.
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pacecar68
Champion Author Oakland

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Message Posted: Feb 16, 2013 10:52:49 AM

follow the owner's manual.
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Titanic1985
Champion Author South Carolina

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Message Posted: Feb 16, 2013 10:37:13 AM

Good Morning Firedawg99. There is a vast difference between the words "recommends" and "suggest". Most Owner's Manuals clearly state what is REQUIRED for your vehicle to operate properly. What would help you and fellow Gas Buddies is to provide the exact wording and information about the vehicle and its engine.

From your last sentence, I am assuming (that usually gets me into trouble) that the engine was designed to run on a higher Octane rating than 87. If that be the case, yes it would be prudent to use it before filling up with 93 Octane. I would suggest driving the vehicle gently as you are dealing with engine timing (pre-detonation & post detonation) and perhaps variable valve timing (my engine has this). The computer can only "adjust" an engine so much. Using 87 Octane shouldn't cause major problems one time unless you really push the limits on the engine.

I also question what would be an "emergency" condition that would prompt someone to use 87 Octane instead of 93 Octane or why that would be mentioned in the Owner's Manual.

I found an Exxon FAQ document which may help you:

Exxon Fuel Frequently Asked Questions

You will note that it refers you to your Owner's Manual for the recommended fuel. You can also read other articles by doing a Google search on "gasoline octane". Best Wishes :-) . MGY

[Edited by: Titanic1985 at 2/16/2013 10:39:05 AM EST]
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Firedawg99
Sophomore Author Virginia

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Message Posted: Feb 14, 2013 11:16:07 PM

Thanks for the info. I just like to see what everyone says.
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DriverMatt
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Message Posted: Feb 8, 2013 6:36:10 PM

I made the mistake of buying a "premium only" car once before but never again. I used 87 a few times but would agree that its best using what the owners manual calls for.
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PatAZ
Champion Author Tucson

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Message Posted: Feb 8, 2013 5:40:57 PM

If you can't afford to run premium as the manual says you can't afford the car. If it was a one time mistake
don't worry about it.
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diesel8888
Champion Author Salt Lake City

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Message Posted: Feb 8, 2013 11:27:53 AM

I've done this in the past. It won't ruin your car, but you will feel the weaker response when you need it.
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Saab93turbo
Champion Author Washington

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Message Posted: Feb 8, 2013 11:24:40 AM

A few cars (usually more than 10 years old) require premium. I wonder if they mean 91 octane (premium in most or all of California)?
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kellyoneal
Champion Author Louisville

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Message Posted: Feb 8, 2013 10:56:49 AM

93 will make it run better
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JimBlake56
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Message Posted: Feb 8, 2013 9:25:57 AM

I think it's more often related to advertized power. If a carmaker wants to claim a bit more power, they can tune the enigne to take advantage of the higher anti-knock-index. Then they'll say to use 91-AKI "recommended".

That doesn't always mean a lower AKI will do any damage. The damage question needs to address the "minimum required" AKI, rather than the "recommended" fuel.

Still, there's probably a few cars where the EM will back off the spark or boost just a bit too slowly, and lower AKI might just cause trouble over the long term. But you can't just make a blanket statement for any & all cars because I think that situation is not very common. You have to ask that question for a very specific engine.
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bluenvoy
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Message Posted: Feb 8, 2013 9:24:16 AM

Use what the owner's manual says to use. You don't want the pinging from not having the right octane.
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gvan
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Message Posted: Feb 8, 2013 9:18:03 AM

There is a difference between recommended and required. If it is required, then you should use premium. If it is recommended I see no reason why you couldn't use 87 octane.
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OilerFan
Champion Author Tulsa

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Message Posted: Feb 8, 2013 5:19:18 AM

THere's a reason that manufacturer recommends a particular grade. They feel comfortable with their warranty at a particular grade, but don't with other grades; so I stick with what they recommend.
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MertieMan
Champion Author Lexington

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Message Posted: Feb 8, 2013 5:12:13 AM

If the owners says to burn it, by all means burn it.
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jes
Champion Author Pennsylvania

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Message Posted: Feb 8, 2013 5:00:18 AM

Follow the owners manual. Fuel octane recommendations is one of the first things I take into consideration when purchasing a vehicle.
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probedude2
Champion Author Akron

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Message Posted: Feb 8, 2013 12:48:07 AM

It won't damage the engine, but your fuel economy will be noticeably worse, so it may be the better deal to use premium
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14smoke
Champion Author Birmingham

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Message Posted: Feb 7, 2013 4:19:49 PM

The computer will retard the timing so you won't get that knocking sound that used to be associated with running low octane fuel in a car requiring higher octane. However, if the manufacturer recommends it, the performance will suffer and, over the long-term, yes, it could cause damage to the internals of the engine.

I wouldn't do it often.
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GrumpyCat
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Message Posted: Feb 7, 2013 2:17:35 PM

It could.

But one should also differentiate between a "recommended" fuel and the specified minimum requirements. Many who purchase high end vehicles want to be told they have to spend lots of money to keep it happy and those who write the owner's manuals know how to keep their clientele happy.

"Your car is so good that it has to have the most expensive gasoline you can find."

"Your car is so good it has to have the most expensive synthetic motor oil you can find."

"Only authorized <fill in the blank> dealers have mechanics smart enough to keep your car running."

In 2000 Toyota worded the Avalon owner's manual to say to owners who wanted to have to buy premium that they should do so. But to a careful reader it said 87 octane was the specified fuel used for EPA ratings.
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