Sunoco Racing Fuel
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
I'm sure it will if there was a lot of moving air but isn't there only so much moisture in air and once the cap is closed, where is the fresh air coming from with moisture? Now if you are talking about your boat at the Marina, I agree. If we go with a 20 gallon tank, whether it is 5 gallons full or 15, how much more water will you get that is going to be significant? If I get a gallon of water after it sits for 4 months, I'd be crapping my pants but if it is 3 drops more, probably not. So my question is, how much more water will you be able to get with the cap on tight and the fuel system not exposed to fresh air?
Burning Brakes
Joined: Aug 2004
Posts: 1,207
Likes: 147
From: St. Louis MO
If you use higher octane fuel than your car "needs", it will actually deliver less power. Higher octane fuel has less power in it. The reason you need high octane fuel is to stop detonation, high octane fuel is less volatile so it doesn't explode in the cylinder rather than burn.
The gas company want you to purchase the highest octane fuel they have,,,,,,, super dooper fuel. SUPER expensive fuel.
The gas company want you to purchase the highest octane fuel they have,,,,,,, super dooper fuel. SUPER expensive fuel.
Raising the octane rating (also known as the anti-knock index) doesn't change the energy content of a gallon of gasoline. A higher octane rating indicates greater resistance to knock, the early combustion of the fuel-air mixture that causes cylinder pressure to spike.
When higher-octane fuel is flowing through its injectors, the engine controller can take advantage of the elevated knock threshold and dial in more aggressive timing and {on supercharged vehicles} higher boost pressures to improve performance.
Cite: Car and Driver August 2019
Le Mans Master
Joined: Jun 2019
Posts: 5,452
Likes: 2,168
From: Loveland
That's exactly what I said. If your car needs 97 octane,,,,, for what ever reason, going to 100 octane isn't going to increase the power output. If your car needs higher octane because of higher boost, then it needs it, going above that number isn't helpful. If your car is pulling back the timing at high throttle, then you NEED higher octane.
Burning Brakes
Joined: Aug 2004
Posts: 1,207
Likes: 147
From: St. Louis MO
Oh ye of little faith!
2. I’ll save you some time, read the third paragraph in the Introduction and if you are still interested spend some time on the entire article. By the way, I was told this tidbit by a chemical engineer I worked with at GE in the 1980’s and he had the math to prove it! This article is enough for me: https://www.sciencedirect.com/scienc...59431104002042
2. I’ll save you some time, read the third paragraph in the Introduction and if you are still interested spend some time on the entire article. By the way, I was told this tidbit by a chemical engineer I worked with at GE in the 1980’s and he had the math to prove it! This article is enough for me: https://www.sciencedirect.com/scienc...59431104002042
Your entire premise falls apart when these salient points are brought to light.
1) the test was undertaken in Turkey, with European gasoline, and the study does not appear to be peer-reviewed.
2) In that study, the effect of higher-octane gasoline on the performance and exhaust emissions was studied using the carburetor gasoline engine.
3) In that study the additives used to increase octane number also influence the emissions. For instance, a study [14] confirms that the tetra alkyl lead in gasoline . . .
4) That chemical engineer you worked was at GE, not at an auto manufacturer, and not a fuels & lubricants researcher, and it's a long way from the 1980’s!
The engine fuels and combustion additives made for older carbureated engines are can show much different results than would be observed in a modern computer controlled fuel injected engine. Citing results from a study almost 20yrs old is questionable at best.
Last edited by fnbrowning; Mar 4, 2024 at 03:50 PM.
Burning Brakes
Joined: Jun 2021
Posts: 801
Likes: 408
From: NC
That's exactly what I said. If your car needs 97 octane,,,,, for what ever reason, going to 100 octane isn't going to increase the power output. If your car needs higher octane because of higher boost, then it needs it, going above that number isn't helpful. If your car is pulling back the timing at high throttle, then you NEED higher octane.
Last edited by Blackwater0323; Mar 4, 2024 at 03:41 PM. Reason: add
Burning Brakes
Joined: Aug 2004
Posts: 1,207
Likes: 147
From: St. Louis MO
That's exactly what I said. If your car needs 97 octane,,,,, for what ever reason, going to 100 octane isn't going to increase the power output. If your car needs higher octane because of higher boost, then it needs it, going above that number isn't helpful. If your car is pulling back the timing at high throttle, then you NEED higher octane.
Also incorrect is your statement regarding 100 octane. Such a blanket statement cannot take into account the apparent density altitude and engine load the ECM is seeing. It has been observed often that an engine is pulling timing on hot track days at high loads. If a higher octane gasoline is substituted, knock will be retarded, and the engine controller can take advantage of the elevated knock threshold and dial in more aggressive timing. This almost always shows increased power output.
Le Mans Master
Joined: Jun 2019
Posts: 5,452
Likes: 2,168
From: Loveland
Higher octane fuel in fact does have less power. If your car needs 85 octane and you put 100 octane in it,,,,,, the engine will deliver less power. It is less volatile, it is harder to ignite. That's the point of higher octane.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
Burning Brakes
Joined: Aug 2004
Posts: 1,207
Likes: 147
From: St. Louis MO
Team Owner
Joined: Jul 2004
Posts: 28,431
Likes: 3,284
From: Hartford WI
To a point, yes. That said, just because I can get 120 octane doesn't mean 5he ECM has settings for that. I would think it is only set up for pump gas which is up to 95 but go ask a programmer.
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
Octane doesn't measure stored energy.
Octane measures detonation resistance.
A quick read: https://www.motortrend.com/how-to/15...-about-octane/
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
An ECU can use flex fuel sensors to adjust tables based on alcohol content, but there isn't an octane sensor.
Le Mans Master
Joined: Jun 2019
Posts: 5,452
Likes: 2,168
From: Loveland
I agree with him.
An engine only needs enough octane to prevent detonation; if it's tuned for 91-octane pump gas and has a slight ping on a hot day, filling up with 118-octane race fuel won't add crazy horsepower.
An engine only needs enough octane to prevent detonation; if it's tuned for 91-octane pump gas and has a slight ping on a hot day, filling up with 118-octane race fuel won't add crazy horsepower.
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
Ok, so will you redact your statement that increasing octane leads to less power?
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
See your own statement here:
Higher octane fuel in fact does have less power. If your car needs 85 octane and you put 100 octane in it,,,,,, the engine will deliver less power. It is less volatile, it is harder to ignite. That's the point of higher octane.
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
It is not very smart to quote an article without understanding the article.
Your entire premise falls apart when these salient points are brought to light.
1) the test was undertaken in Turkey, with European gasoline, and the study does not appear to be peer-reviewed.
2) In that study, the effect of higher-octane gasoline on the performance and exhaust emissions was studied using the carburetor gasoline engine.
3) In that study the additives used to increase octane number also influence the emissions. For instance, a study [14] confirms that the tetra alkyl lead in gasoline . . .
4) That chemical engineer you worked was at GE, not at an auto manufacturer, and not a fuels & lubricants researcher, and it's a long way from the 1980’s!
The engine fuels and combustion additives made for older carbureated engines are can show much different results than would be observed in a modern computer controlled fuel injected engine. Citing results from a study almost 20yrs old is questionable at best.
Your entire premise falls apart when these salient points are brought to light.
1) the test was undertaken in Turkey, with European gasoline, and the study does not appear to be peer-reviewed.
2) In that study, the effect of higher-octane gasoline on the performance and exhaust emissions was studied using the carburetor gasoline engine.
3) In that study the additives used to increase octane number also influence the emissions. For instance, a study [14] confirms that the tetra alkyl lead in gasoline . . .
4) That chemical engineer you worked was at GE, not at an auto manufacturer, and not a fuels & lubricants researcher, and it's a long way from the 1980’s!
The engine fuels and combustion additives made for older carbureated engines are can show much different results than would be observed in a modern computer controlled fuel injected engine. Citing results from a study almost 20yrs old is questionable at best.
Burning Brakes
Joined: Jan 2019
Posts: 954
Likes: 376
From: Louisiana
If your car needs 85 octane and you put 100 octane in it,,,,,, the engine will deliver less power
Burning Brakes
Joined: Aug 2004
Posts: 1,207
Likes: 147
From: St. Louis MO
In point of fact it is possible for a high-performance automobile to see detonation at certain altitudes, temperatures/relative humidity levels that would not show detonation otherwise. The ECM will dial in knock retard, and that will equal a loss of power. Conversely, injecting your referenced 100 octane fuel will retard knock and in the absence of a knock imput, the engine controller can take advantage of the elevated knock threshold and increase the timing in a more aggressive manner to the limits of the internal timing tables. This almost always shows increased power output. Not a lot, but measurable, as seen in the that same August 2019 Car and Driver article I referenced.