what octane should i use?
07-02-04, 12:10 PM
#1
Rex7
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what octane should i use?
i have an 88 vert. i heard using 87octane is better? is this true?and i heard using a higher octane gas is better for your car.what do you guys use, and suggest for me to use?Thanks
07-02-04, 12:17 PM
#2
In a non-turbo, lower octane is better. The engine doesn't need the knock resistance, and lower octane fuel burns cleaner, leaving less carbon buildup. Plus it's cheaper.
So, pretty much, the lowest you can find. Unless you have a turbo. Then the highest you can find.
-=Russ=-
So, pretty much, the lowest you can find. Unless you have a turbo. Then the highest you can find.
-=Russ=-
07-02-04, 01:31 PM
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Originally posted by Syonyk
In a non-turbo, lower octane is better. The engine doesn't need the knock resistance, and lower octane fuel burns cleaner, leaving less carbon buildup. Plus it's cheaper.
So, pretty much, the lowest you can find. Unless you have a turbo. Then the highest you can find.
-=Russ=-
In a non-turbo, lower octane is better. The engine doesn't need the knock resistance, and lower octane fuel burns cleaner, leaving less carbon buildup. Plus it's cheaper.
So, pretty much, the lowest you can find. Unless you have a turbo. Then the highest you can find.
-=Russ=-
-Joe
07-02-04, 01:43 PM
#6
Originally posted by OverDriven
Right on. BTW...I didn't know that lower octane burns cleaner. I thought that higher octane was more refined, thus there are less impurities. From what I undertand, its the impurities in the gas that can cause a chain reaction leading to detonation. So why then does lower octane burn cleaner if it is less refined?
-Joe
Right on. BTW...I didn't know that lower octane burns cleaner. I thought that higher octane was more refined, thus there are less impurities. From what I undertand, its the impurities in the gas that can cause a chain reaction leading to detonation. So why then does lower octane burn cleaner if it is less refined?
-Joe
Here is some interesting reading:
The name "octane" comes from the following fact: When you take crude oil and "crack" it in a refinery, you end up getting hydrocarbon chains of different lengths. These different chain lengths can then be separated from each other and blended to form different fuels. For example, methane, propane and butane are all hydrocarbons. Methane has a single carbon atom. Propane has three carbon atoms chained together. Butane has four carbon atoms chained together. Pentane has five, hexane has six, heptane has seven and octane has eight carbons chained together.
It turns out that heptane handles compression very poorly. Compress it just a little and it ignites spontaneously. Octane handles compression very well -- you can compress it a lot and nothing happens. Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane).
More:
A high octane rating ensures that it takes a REALLY hot ignition source to ignite the fuel (such as a spark plug or the flame-front itself) and not just the rise in pressure & temperature that's a result of normal combustion. Note that the thermal rises in the cylinder are in direct proportion to the compression ratio of the engine (more below). The higher the compression ratio, the higher the octane of the fuel that's needed.
Octane rating is in no way correlated with engine power or efficiency. There is more potential energy in a gallon of diesel fuel than a gallon of gasoline, yet the diesel fuel has a much lower octane value (more on that below).
07-02-04, 05:24 PM
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Originally posted by OverDriven
I didn't know that lower octane burns cleaner. I thought that higher octane was more refined, thus there are less impurities. From what I undertand, its the impurities in the gas that can cause a chain reaction leading to detonation. So why then does lower octane burn cleaner if it is less refined?
I didn't know that lower octane burns cleaner. I thought that higher octane was more refined, thus there are less impurities. From what I undertand, its the impurities in the gas that can cause a chain reaction leading to detonation. So why then does lower octane burn cleaner if it is less refined?
The octane rating has nothing to do with clean burning, as it is simply an anti-knock rating.
Originally posted by Syonyk
So, pretty much, the lowest you can find. Unless you have a turbo. Then the highest you can find.
So, pretty much, the lowest you can find. Unless you have a turbo. Then the highest you can find.
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07-02-04, 08:14 PM
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It turns out that heptane handles compression very poorly. Compress it just a little and it ignites spontaneously. Octane handles compression very well -- you can compress it a lot and nothing happens. Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane).
07-03-04, 01:55 AM
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Originally posted by BDoty311
Well what does fuel with over 100 octane contain?
Well what does fuel with over 100 octane contain?
Actual gasoline contains quite a few ingredients. Higher-octane fuel contains hydrocarbons or other ingredients that have better anti-knock properties than pure octane, hence the over-100 octane rating.
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