Premium vs. Regular
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Joined: Jan 2004
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From: limerick
DUDE READ THE FREAKIN MANUAL!
How much of a moron does anyone have to be to not know that? There must be 1000 post on this and they all say and know the same thing. You want to hurt your performance and engine and save what $2.00 a fill up be my guest.
How much of a moron does anyone have to be to not know that? There must be 1000 post on this and they all say and know the same thing. You want to hurt your performance and engine and save what $2.00 a fill up be my guest.
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Joined: May 2002
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From: USA
I run what the manual says.
I was just in a gas discussion on another board.
Hard, empirical research has borne out time and again that a well-tuned late-model engine (OBDII) runs best on fuel within specifications made by the manufacturer. Running higher octane fuel when you car doesn't call for it is almost always a waste of money, no matter what the seat of your pants or your brother-in-law the mechanic says. Engines without knock sensors, older engines with carbon deposits, and engines with the effective compression ratio modified (i.e., supercharged) will need the premium stuff. You can safely run the octane the manufacturer recommends. If it doesn't knock under load, stay with it.
This link is below is pretty interesting. One of the things they did was put 87 octane in a new BMW M3 and compared the results. Read this link in depth. There is some really good info in here.
There are three pages total:
http://www.caranddriver.com/xp/Caranddriver/features/2001/november/200111_featur e_gasoline.xml://http://www.caranddriver.com/xp/Cara... e_gasoline.xml
I was just in a gas discussion on another board.
Hard, empirical research has borne out time and again that a well-tuned late-model engine (OBDII) runs best on fuel within specifications made by the manufacturer. Running higher octane fuel when you car doesn't call for it is almost always a waste of money, no matter what the seat of your pants or your brother-in-law the mechanic says. Engines without knock sensors, older engines with carbon deposits, and engines with the effective compression ratio modified (i.e., supercharged) will need the premium stuff. You can safely run the octane the manufacturer recommends. If it doesn't knock under load, stay with it.
This link is below is pretty interesting. One of the things they did was put 87 octane in a new BMW M3 and compared the results. Read this link in depth. There is some really good info in here.
There are three pages total:
http://www.caranddriver.com/xp/Caranddriver/features/2001/november/200111_featur e_gasoline.xml://http://www.caranddriver.com/xp/Cara... e_gasoline.xml
Joined: Jul 2004
Posts: 3,319
Likes: 14
Originally Posted by Road & Track
An engine's tendency to knock is influenced most by its compression ratio, although combustion-chamber design also has a large effect. A higher ratio extracts more power during the expansion stroke, but it also creates higher cylinder pressures and temperatures, which tend to induce knock. In supercharged engines boost pressure behaves the same way. That's why the highest-performance engines require higher-octane fuel.
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Joined: Jan 2004
Posts: 4,938
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From: limerick
Originally Posted by Jason B,Mar 10 2005, 02:17 PM
I run what the manual says.
I was just in a gas discussion on another board.
Hard, empirical research has borne out time and again that a well-tuned late-model engine (OBDII) runs best on fuel within specifications made by the manufacturer. Running higher octane fuel when you car doesn't call for it is almost always a waste of money, no matter what the seat of your pants or your brother-in-law the mechanic says. Engines without knock sensors, older engines with carbon deposits, and engines with the effective compression ratio modified (i.e., supercharged) will need the premium stuff. You can safely run the octane the manufacturer recommends. If it doesn't knock under load, stay with it.
This link is below is pretty interesting. One of the things they did was put 87 octane in a new BMW M3 and compared the results. Read this link in depth. There is some really good info in here.
There are three pages total:
http://www.caranddriver.com/xp/Caranddriver/features/2001/november/200111_featur e_gasoline.xml://http://www.caranddriver.com/xp/Cara... e_gasoline.xml://http://www.caranddriver.com/xp/Cara... e_gasoline.xml
I was just in a gas discussion on another board.
Hard, empirical research has borne out time and again that a well-tuned late-model engine (OBDII) runs best on fuel within specifications made by the manufacturer. Running higher octane fuel when you car doesn't call for it is almost always a waste of money, no matter what the seat of your pants or your brother-in-law the mechanic says. Engines without knock sensors, older engines with carbon deposits, and engines with the effective compression ratio modified (i.e., supercharged) will need the premium stuff. You can safely run the octane the manufacturer recommends. If it doesn't knock under load, stay with it.
This link is below is pretty interesting. One of the things they did was put 87 octane in a new BMW M3 and compared the results. Read this link in depth. There is some really good info in here.
There are three pages total:
http://www.caranddriver.com/xp/Caranddriver/features/2001/november/200111_featur e_gasoline.xml://http://www.caranddriver.com/xp/Cara... e_gasoline.xml://http://www.caranddriver.com/xp/Cara... e_gasoline.xml
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Joined: Jul 2004
Posts: 386
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From: so cal
i even always used 91 octane on my old car integ GSR..
i only put 91 on my S but 91 is the highest i see around here, SO cal.. do other states or cities have higher than 91 octane gases?? i've seen like a 100 octane at a gas station before but it was like 5.70 a gallon..
i only put 91 on my S but 91 is the highest i see around here, SO cal.. do other states or cities have higher than 91 octane gases?? i've seen like a 100 octane at a gas station before but it was like 5.70 a gallon..
