Anyone use regular gas in their Si?

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I genuinely do not like how "normal" high knock control is portrayed here. In cvt cars some knock control movement is normal and i get that but maxing it out on 1 pull is not at all normal and absolutely could be slowly ruining this guys engine while alot here are saying it would never cause any damage.

I lose my head over seeing even 2-3 knock counts in mine.

The fact of all this is knock count is the computer registering a strange combustion event no matter how you word it. 0 is normal. Any other number is not.

Knock control is the car actively trying to keep the engine from grenading. Cvt owners get the raw deal here because as was stated knock control rises with just high rpm use. Rising is one thing. Insanely high and repeatable is flat out DANGEROUS to engine health.

If i ever see over 70% on my si then the tune is complete garbage and i will wonder how much damage i just did.

Ive had to throw 4 or more degrees of advance on top of 23-24 psi to even get the knock control to react at all.

Given the risks i tend to trust it. They are too high to just shrug shoulders about it.
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eh... that's a widely discussed and disputed grey area.

https://en.wikipedia.org/wiki/Engine_knocking

The ECU will pull timing when it detects knock. Knock is pre-ignition or detonation at an unexpected time. Saying "zero damage will occur" paints quite the harmless picture. IMHO, if an engine is prone to knock, it's not running right and is going to have problems.

Now if someone only fed it regular, the timing would get adjusted kinda permanently (effectively enough). The engine would make less power and would be a sad example of how it can run on lower octane fuel.

I'd say giving the engine 91 octane is a minimum since some areas do not have 92 or higher available. Running the engine on 87 octane because "it will adjust to the fuel and back off timing...." is just a horrible idea.
I'm not disputing that one should NOT put premium in their cars. It is recommended. Now saying that, if there was any chance of 87 causing damage (I'm talking strictly non-tuned stock engine), it would not be recommended but MANDATORY. For example, my Lexus has a clear warning on the fuel cap "PREMIUM UNLEADED ONLY!" There is no such warning on the Si. Again, talking strictly stock with no bolt-ons or tunes
 

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https://blog.firestonecompleteautocare.com/maintenance/what-causes-engine-knocking/

Low-Octane Fuel
What’s happening: Gasoline comes with different octane ratings, which is why you have so many options when you pull up to the pump. The higher a fuel’s octane rating, the more compression it can withstand before igniting. If your engine was engineered to handle high-octane fuel, using the regular kind could lead to excess engine noise.

Why it matters: High-octane fuel does tend to be more expensive than regular fuel. While saving a few bucks at the pump may seem like a great reason to go with regular, engine knocking means it may be time to spend a little more. Long-term use of the wrong fuel could damage your engine and decrease your fuel economy. When you’re getting fewer miles per gallon—and potentially paying for engine repairs down the line—cheaper gasoline won’t be saving you any money at all.

What to do: First, check your owner’s manual. What’s your recommended fuel type and are you using it? If needed, step up your octane level at your next fill up or use an octane booster to increase performance. If this doesn’t seem to help after a few fill-ups, your problem might stem from something else.
 

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Well, he is proposing a ban of flavored nicotine vape juice due to the sale of lousy THC vitamin e acetate juice.... making the USA again look like a circus led by a clown
I'm not a fan of the President (as is probably clear), but vaping has been proven as the cause of several deaths. Anyway, another topic for another time...
 


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The difference in "recommended" and "required" is just a difference in vocabulary geared toward the client base of who the manufacturer is trying to sell to.

"I ain't buying no Honda that needs premium!" Recommended.

"Well my Lexus NEEDS the most expensive gas because it's special!" Required.

Both will run on whatever because of modern computers. And both were designed with premium in mind.

Do what you want. Less than 91 is ill advised.
 

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I genuinely do not like how "normal" high knock control is portrayed here. In cvt cars some knock control movement is normal and i get that but maxing it out on 1 pull is not at all normal and absolutely could be slowly ruining this guys engine while alot here are saying it would never cause any damage.

I lose my head over seeing even 2-3 knock counts in mine.

The fact of all this is knock count is the computer registering a strange combustion event no matter how you word it. 0 is normal. Any other number is not.

Knock control is the car actively trying to keep the engine from grenading. Cvt owners get the raw deal here because as was stated knock control rises with just high rpm use. Rising is one thing. Insanely high and repeatable is flat out DANGEROUS to engine health.

If i ever see over 70% on my si then the tune is complete garbage and i will wonder how much damage i just did.

Ive had to throw 4 or more degrees of advance on top of 23-24 psi to even get the knock control to react at all.

Given the risks i tend to trust it. They are too high to just shrug shoulders about it.
But you are tuned, correct? If one is tuned, TSP, Ktuner etc. all say premium is mandatory
 

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So in my opinion - knock = damage.

Does your opinion differ?
Depends on the knock. Is it LSPI type knock? Yes, damage. Is it audible knock (pinging sound)? Over time that type of knock can cause damage. Is it knock that the knock control detects and then pulls timing? I doubt it is causing damage. If using 87 causes damage to an engine, Honda would have made Premium mandatory and not recommended. Again, I am talking stock engine
 

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But you are tuned, correct? If one is tuned, TSP, Ktuner etc. all say premium is mandatory
Correct.

If mine was stock with crazy knock control that i somehow knew about i wouldn't keep it.

If God himself spends 4 weeks tuning my car and tells me knock control to that degree was normal, id slap him in the face for trying to kill my motor, return to stock, sell the car, and start over.
 
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This argument has been done to death. Do you think a manufacturer would risk thousands and probably hundreds of thousands of law suits by putting "Recommended" premium instead of "Required" premium if doing so could potentially cause harm? Answer is NO..put 87 octane if you want you'll be fine but your car won't run to its full potential, thats it.
 


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The difference in "recommended" and "required" is just a difference in vocabulary geared toward the client base of who the manufacturer is trying to sell to.

"I ain't buying no Honda that needs premium!" Recommended.

"Well my Lexus NEEDS the most expensive gas because it's special!" Required.

Both will run on whatever because of modern computers. And both were designed with premium in mind.

Do what you want. Less than 91 is ill advised.
I'm not advocating using 87. Never said that. I only used premium from the day of ownership to the day of sale. All I am saying is that 87 will only hurt performance. Anyway, this is sort of a useless argument, everyone has their opinion anyway and are going to use any gas they want. Honda doesn't say its mandatory, so if a person chooses not to put the "best grade" in their cars, no one should really care
 

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My friend, you seem a bit upset today. Did our President say something today (again) to upset the balance of the world?
I’m on vacation for 4 days and it just boggles my mind that an Si owner would run 87 in their car... I’m actually in a happy place @amirza786 ! You know what? Throw whatever in your Si, even diesel. I’ve heard that you can gain 40lbs/ft stock running diesel!
 

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Depends on the knock. Is it LSPI type knock? Yes, damage. Is it audible knock (pinging sound)? Over time that type of knock can cause damage. Is it knock that the knock control detects and then pulls timing? I doubt it is causing damage. If using 87 causes damage to an engine, Honda would have made Premium mandatory and not recommended. Again, I am talking stock engine
Your so close to the truth! Any sort of lspi pre detonation, pinging, detonation, knock, whatever label you use.... is still causing cumulative damage.

This is how all modern fuel injected knock systems function:

Hit gas > Engine pings> slight damage occurs> computer reacts by pulling timing>let off gas.

Keep cruising and computer returns to normal> hit gas>engine pings> slight damage occurs> computer reacts by pulling timing> let off gas.

Rarely are normal drivers at a load that can create detonation so they can get away with this for a long long time.
 

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I’m on vacation for 4 days and it just boggles my mind that an Si owner would run 87 in their car... I’m actually in a happy place @amirza786 ! You know what? Throw whatever in your Si, even diesel. I’ve heard that you can gain 40lbs/ft stock running diesel!
It seems your under the impression that I used 87 when I only used 91 (past tense, since I don't own the Si anymore). Anyway bro, enjoy your vacation, and get in the water. Vacations should be computer free!
 

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Your so close to the truth! Any sort of lspi pre detonation, pinging, detonation, knock, whatever label you use.... is still causing cumulative damage.

This is how all modern fuel injected knock systems function:

Hit gas > Engine pings> slight damage occurs> computer reacts by pulling timing>let off gas.

Keep cruising and computer returns to normal> hit gas>engine pings> slight damage occurs> computer reacts by pulling timing> let off gas.

Rarely are normal drivers at a load that can create detonation so they can get away with this for a long long time.
Well, I believe 100 percent that premium fuel should be used with this engine. That is all I used from the day I drove it off the dealers lot...
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