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Old 09-03-2005, 07:34 AM   #1
GMMerlin
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Thumbs up The truth about gasoline

Here is some info about gasoline


A number of myths about octane have grown over the
years. There is a widespread perception that the greater the
octane the better the performance. However, once enough
octane is supplied to prevent engine knock, there is little, if
any, performance improvement. One exception to this would
be in vehicles equipped with knock sensors. In these vehicles,
if octane is insufficient, the computer will retard the timing to
limit engine knock. If the vehicle is operating in the “knock
limiting” mode (retarded timing), using a higher octane fuel will
allow timing to be advanced, resulting in some level of
performance increase. However, even in these vehicles,
tests have shown that there is no perceptible performance
improvement from using a fuel of higher octane than that
recommended by the vehicle manufacturer.
Another myth is that using a higher octane fuel will result
in improved fuel economy (increased miles per gallon). Octane
is nothing more than a measure of anti-knock quality.
Fuel economy is determined by a number of variables including
the energy content of the fuel. Some premium grades of
fuel may contain components which increase energy content.
In those cases, fuel economy may improve slightly as a result
of higher energy content, but not as a result of the higher
octane. Two fuels of identical octane could have different
energy content due to compositional differences.
Consumers need only use a gasoline meeting the
vehicle manufacturer’s recommended octane levels. If engine
knocking occurs on such fuels and mechanical causes
have been eliminated, then the consumer should purchase
the next highest octane gasoline (above the manufacturer's
recommendation in the owners manual) that will provide
knock-free operation.

GO HERE FOR MORE INFO
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Old 03-08-2006, 08:30 PM   #2
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Re: The truth about gasoline

Quote:
Originally Posted by GMMerlin
Here is some info about gasoline


A number of myths about octane have grown over the
years. There is a widespread perception that the greater the
octane the better the performance. However, once enough
octane is supplied to prevent engine knock, there is little, if
any, performance improvement. One exception to this would
be in vehicles equipped with knock sensors. In these vehicles,
if octane is insufficient, the computer will retard the timing to
limit engine knock. If the vehicle is operating in the “knock
limiting” mode (retarded timing), using a higher octane fuel will
allow timing to be advanced, resulting in some level of
performance increase. However, even in these vehicles,
tests have shown that there is no perceptible performance
improvement from using a fuel of higher octane than that
recommended by the vehicle manufacturer.
Another myth is that using a higher octane fuel will result
in improved fuel economy (increased miles per gallon). Octane
is nothing more than a measure of anti-knock quality.
Fuel economy is determined by a number of variables including
the energy content of the fuel. Some premium grades of
fuel may contain components which increase energy content.
In those cases, fuel economy may improve slightly as a result
of higher energy content, but not as a result of the higher
octane. Two fuels of identical octane could have different
energy content due to compositional differences.
Consumers need only use a gasoline meeting the
vehicle manufacturer’s recommended octane levels. If engine
knocking occurs on such fuels and mechanical causes
have been eliminated, then the consumer should purchase
the next highest octane gasoline (above the manufacturer's
recommendation in the owners manual) that will provide
knock-free operation.

GO HERE FOR MORE INFO
Here is a simple way to explain . try holding a lighter to 108 octane fuel . It will hardly burn you have to keep a flame on it for it to burn. Well on the other hand try doing this to 87 octane . We all no how fast it will blaze . The higher the octane the slower it burns so this means better fuel mileage. Not more hp.
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Old 03-16-2006, 02:21 PM   #3
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Re: The truth about gasoline

my 77 chevy p/u gets better MPG on 87 not 92 oct. fuel
it doesn't need it
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Old 03-17-2006, 03:16 AM   #4
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Re: The truth about gasoline

Quote:
Originally Posted by comp
my 77 chevy p/u gets better MPG on 87 not 92 oct. fuel
it doesn't need it
Sure it does . Just like evertything else does. Hey, we dont even need 92 octane . Get real dude
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Old 03-23-2006, 06:22 PM   #5
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Re: The truth about gasoline

Quote:
Originally Posted by TLBLZER
Here is a simple way to explain . try holding a lighter to 108 octane fuel . It will hardly burn you have to keep a flame on it for it to burn. Well on the other hand try doing this to 87 octane . We all no how fast it will blaze . The higher the octane the slower it burns so this means better fuel mileage. Not more hp.



your way off on your "lighter thing" you will hardly notice a difference.

but higher octane will not give you better gas mileage, and it WILL give you more HP (but only because of the timing advance change your computer makes)
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Old 03-23-2006, 06:23 PM   #6
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Re: The truth about gasoline

Quote:
Originally Posted by TLBLZER
Sure it does . Just like evertything else does. Hey, we dont even need 92 octane . Get real dude
it is very very rare for a car to need 92 octane, unless you somehow drive a car with 11:1 compression
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Old 03-23-2006, 06:37 PM   #7
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Re: The truth about gasoline

Quote:
Originally Posted by TLBLZER
Sure it does . Just like evertything else does. Hey, we dont even need 92 octane . Get real dude
i am real,,,, what about a boosted car,,, now they do like it
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Old 04-05-2006, 09:59 PM   #8
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Re: The truth about gasoline

Here's all you really need to know, as long as you stick w/ a Chevron Brand gas you'll be fine. If your engine knocks answer it by getting it some Chevron w/ Techron. It will thank you! I have found that Chevron is the only brand that does not allow my vehicles to knock, any octane will work. You don't need the high octane unless your manufacture recommends it, as stated above.
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Old 04-25-2006, 04:28 PM   #9
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Re: The truth about gasoline

High octane fuels are for High compression vehicles only. I have encountered the myth about fuel economy many times, the differance high octane fuel provide in fuel economy (if any) is more than offset by the higher price. I do suggest blown or other high compression vehicles to use a higher octane level but going over 100 is unnessesary for any registered, street legal vehicle. My two cents are in, mind you they are canadian cents so they are not worth as much down there in the states
john

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Old 07-14-2006, 11:21 AM   #10
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Re: The truth about gasoline

Quote:
Originally Posted by victimizati0n
it is very very rare for a car to need 92 octane, unless you somehow drive a car with 11:1 compression
Not THAT rare, my friend. There are a lot of old model cars still out there that need 92 and more. Now if you clarify that to mean cars newer than year 2000, I agree. In general, the original article is correct.
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Old 08-11-2006, 02:16 AM   #11
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Re: The truth about gasoline

Higher octane ratings correlate to higher activation energies. Activation energy is the amount of energy necessary to start a chemical reaction. If you guys drive old vehicles with some real power under the hood you'll see the difference between 87 octane and 93 octane. Try adding 110 racing fuel to the mix. Also Real comparisons cannot be made from tank to tank. Your fuel tank holds a few gallons that dont get used. Adding 93 to a tank that had 87 in it doenst give you 93. Gives you a mix of 87 and 93. I also think more goodies go into 93.
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Old 12-01-2006, 12:28 PM   #12
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It's WW2 Voodoo

YOu can find the story online. Scan under 130 octane aviation fuel.
thanks Reg
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Old 12-02-2006, 04:45 AM   #13
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Re: It's WW2 Voodoo

Quote:
Originally Posted by Reg Saretsky
YOu can find the story online. Scan under 130 octane aviation fuel.
thanks Reg
or you could put the link in
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Old 12-02-2006, 10:19 AM   #14
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good point, comp.

http://www.centennialofflight.gov/es...uel/Tech21.htm

heres one of many sites.

Prof. Walmsley told me , decades ago, that the Americans won the chemistry / Physics, & the allies the tech, war by lettign smart officers & boffins work together & make decsiions without political meddling.

The Gaulieters, right up to Zie Furher, screwed up the home front big time.

Cheers
Reg
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Old 12-02-2006, 10:34 AM   #15
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Re: good point, comp.

Quote:
Originally Posted by Reg Saretsky
http://www.centennialofflight.gov/es...uel/Tech21.htm

heres one of many sites.

Prof. Walmsley told me , decades ago, that the Americans won the chemistry / Physics, & the allies the tech, war by lettign smart officers & boffins work together & make decsiions without political meddling.

The Gaulieters, right up to Zie Furher, screwed up the home front big time.

Cheers
Reg
Thanks
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