Premium gas gives 2-3 more horsepower in turbo models (confirmed by Honda rep)

1. This is not a pump fuel for your road car
2. This tune was optimized for full throttle

Hondata said:

The real facts come from companies like ours that generate the data that companies like Google link to. So, here is today's lesson. We cant speak for other manufacturers, just for the many Honda Civic turbos we have tested.

The car tested is a 17 model MT 1.5 turbo Civic. The tank was filled with 91 octane. The lower pink curve is a run immediately after an ECU reset. Knock control is 100%; the default setting. Three to 4 minutes later after loading up the Civic on the dyno, the knock control stabilized to around 70%. The orange power curve is the result of the knock learning and advanced ignition timing.

In this case we gained 12 hp and 13 lb-ft torque.
The torque gain was everywhere - not just at peak.

Knock control for 87 octane is around 80%
Knock control for 93 octane is 55-60%

These values will vary a little according to fuel quality, air and water temperatures.

The actual power and torque gains will be a little less comparing 87 to 91. We estimate 4-5 hp.

Lessons

• The Civic ECU learns to the octane rating
• The Civic ECU advances and retards the ignition to suit, which increases or decreases the power and torque.

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• Test with 87, and noting the knock control.
• Draining the tank and filling with 93, would take two tankfuls as the tank does not completely empty.
• Test with 93, which is not easily available in California.

ArnoldLayne said:

It is futile to get you out of your bubble but I will reiterate....using a higher octane on a car which is designed to run on 87 octane (aka regular unleaded gas) does not offer any advantage except the higher cost you pay and the money you piss away doing that.

Bogus ECU statement? The only bogus here is the spurious claim you are defending that somehow a higher octane gas would make your car fly.

Pretty much most modern engines use knock control technology to burn fuel and they look for the minimum octane and designed to optimize and burn a range of octane rated fuels. It does not offer any distinct advantages to your fuel efficiency or engine performance to use higher octane gas and this is a myth straight out of a hillbilly text book.

This forum is rife with myths and misinformation and self made theories propagated as truths so I am going to leave this one in that category as well.

You go on using the higher octane fuel thinking it is to going to crank out more horse power on your engine...

It seems half this country now chooses to live in its bubble and believe their own set of 'facts' rather than actual facts and it is a fool's errand to change those people's minds. So I am going to let you live in your alternative reality and 'facty sounding stuff' on this.

For the rest of you who are open to knowing the facts (the real ones...not the alternate reality world ones)...just google 'Is Premium gas better for my car?' and you will come up with several articles on the subject (Caveat Emptor: Just like any search results, you need to separate the wheat from the chaff).

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Truckin said:

Arnold,
I totally respect your opinion. I have done some testing with my car and have noted the following. When I use the regular 87 like the owners manual says I normally get about 40.1 MPG. However, when I switch to 89 Non-Ethanol brand I get about 40.8-41 MPG. Now, I have tested this over multiple tanks with the exact same drive and driving style with each gas type. I think it does make a bit of a difference in my vehicle...., but just my thoughts.

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Quicksipper said:

it's easy to disagree with someone without understanding what your talking about. Googling the answer to a vague question is only going to bring you a general response across all auto makers.

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ArnoldLayne said:

You get 40.8-41 MPG out of a car that is rated 42 MPG on Highway?(under ideal driving conditions in the lab, mind you)

Where exactly do you drive?

I am curious to hear from anyone else who gets 41 mpg on the Honda Civic.

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dc2turbo said:

I have gotten 43mpg a few times on a 100mile trip

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Quicksipper said:

on a tuned civic running 93 at that

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ArnoldLayne said:

You get 40.8-41 MPG out of a car that is rated 42 MPG on Highway?(under ideal driving conditions in the lab, mind you)

Where exactly do you drive?

I am curious to hear from anyone else who gets 41 mpg on the Honda Civic.

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ArnoldLayne said:

Oh I understand exactly what I am talking about. Meanwhile you are dancing around with some semantics on 'top tier' gasoline and stuff you overheard from some salesman at Honda as your factual basis for using high octane gasoline.

General response from automakers? No, it is the mechanics of modern cars and they all work the same way without exception.

There is absolutely no benefit...zero, zip, nada, zilch...to using a high octane fuel on a modern car that is designed to run on regular gasoline and recommended by the manufacturer. And this is a scientifically proven fact over and over again.

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Hondata said:

No you cannot expect to gain 12 HP. Maybe 7-8. That is a best guess. A rigorous test would involve;

• Test with 87, and noting the knock control.
• Draining the tank and filling with 93, would take two tankfuls as the tank does not completely empty.
• Test with 93, which is not easily available in California.

There were no mods on the car. It was stock. Octane helps, but the best performance mod for the dollar is the FlashPro.

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