Octane boosters?????

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The octane ratings we see on gas pumps (87, 89, 93, 94) result from mixing a station's base fuel with some of their top fuel, no?

Is the high octane level of top fuel created by a single ingredient?

If so, get some of that. Easy.
No. Base gasoline is made of many different ingredients that have different octanes. Higher octane base fuel has more percentage of the higher octane component in it. It isn't an additive.


In the Midwest and many parts of the country the base gas is 85 octane or 91 octane shipped to terminals. 10% ethanol or 91 octane or both are added at the terminals to make the requested octane of fuel. If you see higher than 91 e0 or 93 e10 there is a different higher octane base used or added to the other base fuels till you get the requested octane.
 
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E-30 is most likely around 91ish octane already. Every 5% ethanol content roughly adds a point of octane to a point. Over the counter octane boosters don't do much and are mostly a waste of money.

Depends on what it does. A lot of octane boosters are just fuels with high octane ratings like ethanol, MTBE, or xylene. So they boost goes down as the concentration goes up.

Other additives like tetraethyl lead and MMT work differently. They apparently prevent premature ignition in the mixture, where it improves the octane rating regardless of the octane rating of the base fuel, and doesn't require a whole lot.

A lot of octane boosters in a bottle are apparently just the former, so just that tiny bottle isn't going to do much.
 

TiGeo

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I tried the Lucas product with before/after logging on my Sportwagen and did see an improvement on that tank with knock retard but not as good as just running a few gallons of E85. It showed as Mn (or was it Mg....) in my UOA that oil change. Can turn your spark plugs orange.
 
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No. Base gasoline is made of many different ingredients that have different octanes. Higher octane base fuel has more percentage of the higher octane component in it. It isn't an additive.


In the Midwest and many parts of the country the base gas is 85 octane or 91 octane shipped to terminals. 10% ethanol or 91 octane or both are added at the terminals to make the requested octane of fuel. If you see higher than 91 e0 or 93 e10 there is a different higher octane base used or added to the other base fuels till you get the requested octane.

I found this presentation which explains how ethanol is used to increase octane and what the other alternatives are/were:

 

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Can we focus on this? :oops:

Trial and error. And obviously a lot of stuff didn't work. Some apparently did but had problems due to either cost effectiveness or other concerns. I found the original story, although I had to get it from an archive since the original article has been purged.

I also have an issue that many of these articles make no mention of what "octane" is - like it's just some sort of property of the fuel or even the proportion of actual octane in the fuel, and not a chemical that's the reference fuel to compare relative antiknock properties.

In the laboratories of Charles Kettering, however, the search for a gasoline additive to cure "knock" had been going on for some years prior to Midgley's rediscovery of TEL. In 1911 Kettering had invented the electric self-starter--a landmark development in automotive history that eliminated dangerous hand-cranking and enabled many Americans (particularly women) to drive for the first time, arguably killing steam and electric cars in the process. This invention would make "Boss" Kettering rich, famous and beloved to a nation falling in love with its wheels. Thanks to the starter, the folksy inventor's new firm, Dayton Engineering Laboratories Company, or DELCO, received its first big order, for $10 million, from the upstart General Motors Corporation, founded only three years earlier by William Crapo Durant.​
GM's 1912 Cadillac was equipped with DELCO's self-starter and battery ignition. When customers reported that the engine of this luxury automobile had an alarming tendency to knock--a sharp, metallic sound hinting at damage being done inside the engine--critics blamed Kettering's electrical components.​
Kettering was convinced, rightly, that knocking was a function of an engine's fuel rather than ignition problems. When Kettering and his partners sold DELCO to Durant's GM and its new partner--Alfred Sloan's Hyatt Roller Bearings--in 1916, his lab was already engaged in a search for the cure. Following the sale, this work was transferred to his new firm, the Dayton Research Laboratories, where a newly hired assistant, Thomas Midgley, was assigned to study the problem of engine knock.​
Stabbing in the dark, Midgley got lucky quickly when he added iodine to the fuel, stopping knock in a test engine and establishing for all time that the malady--premature combustion of the fuel/air mixture--was connected to the explosive qualities of the fuel, what would later be called "octane." Iodine raised octane and cured knock; however, it was corrosive and prohibitively expensive. Inspired by the fundamental breakthrough, Midgley nonetheless carried on with fuel research, testing every substance he could find for antiknock properties, "from melted butter and camphor to ethyl acetate and aluminum chloride." Unfortunately, "most of them had no more effect than spitting in the Great Lakes."​

This mentioned others that were tried, where iodine was the first that seemed to work. Others worked including aniline, but apparently that stunk up everything so bad that it was determined to be unsuitable.

 
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Kettering was convinced, rightly, that knocking was a function of an engine's fuel rather than ignition problems.
Odd. Because fuel is just one thing that can legitimately contribute to knock, including ignition and other engine systems. I guess they're implying that at the time, they had knock when all other causes were ruled out.
 
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Odd. Because fuel is just one thing that can legitimately contribute to knock, including ignition and other engine systems. I guess they're implying that at the time, they had knock when all other causes were ruled out.

It was probably the one thing that was easiest to control at the time. I'm sure that then (as now) that the fuels at the time weren't anywhere near as good as they are today. I was reading that in the early 1930s a typical unleaded fuel would be 60 octane (RON) before lead was more common in the mid-30s. I remember seeing a parade where a Model A club was participating, and one of the drivers said they work fine on modern unleaded. Not sure what they do about the issues with ethanol though. I'd think any car that old still running has had its hoses and linings replaced several times and most recently with modern materials compatible with ethanol, but water absorption will probably be an issue without a sealed fuel system.

I do recall hearing that a Rolls-Royce Merlin engine needed 150 octane (RON?) since it was a 6:1 compression ratio but with 25 PSI boost. I'm wondering how much lead would have needed.
 

TiGeo

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93 octane and 21 psi/14.5 degrees of advance and maybe a hint of knock-retard....modern ECUs are a wonderful thing!
 
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