89 octane = reduced mpg
#61
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Rep Power: 0 idk if this was listed but the higher the octane the harder it is to burn the fuel.. aka 93 octane takes a lot more compression to burn molecules as compared to 89 or 87. Hence the reason for Diesel which is running at a crisp avg of 18:1 or 23:1 compression. So the point in putting in 89 is just going to waste your money . and you can actually do damage sometimes if you run too high of an octane that is not needed for your engine.
I was thinking about goin with 89 for the winter because the gas is more oxygenated so im gonna lose MPG and small amounts of power that i wont notice.
I was thinking about goin with 89 for the winter because the gas is more oxygenated so im gonna lose MPG and small amounts of power that i wont notice.
In the winter, you have more available oxygen to burn, however, the temperatures are much cooler so higer octane is not needed.
Basically, octane should be related to heat, not so much compression (as heat is created by compression). Aluminum heads, having a clean burning combustion chamber, and being able to expel exhaust (heat), will allow you to run lower octane. 20 years ago, 10:1 or higher was unheard of on a street car that was made to run on low-grade gasoline.
Diesels run on such high octane (diesel fuel) because the create a lot of heat from the compression. They are also MUCH more effecient than a gasoline engine.
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Rep Power: 295 wow those of you who use anything more than 87 in a stock civic are pretty uninformed...
basically the higher the octane on gas is the harder it is to burn
higher octane gas will not improve mileage or power because if your car is not suited for it than it will have a harder time burning all of the fuel that is in the cylinder...
when an engine compresses an air fuel mixture its usually designed to run on a certain fuel so all of the mixture is burned and you get the most out of the cycle...
but once u put higher octane fuels in the system designed for lower octane fuels it has a harder time burning because its compression isnt creating enough heat to burn all of it when the spark plug ignites so a lot of excess fuel is dumped out but is filtered by the catalytic converter thats why you dont smell it but it still is getting dumped out...it makes your car run rich, and uses up more gas so you're actually getting less gas mileage out of your car...
basically the higher the octane on gas is the harder it is to burn
higher octane gas will not improve mileage or power because if your car is not suited for it than it will have a harder time burning all of the fuel that is in the cylinder...
when an engine compresses an air fuel mixture its usually designed to run on a certain fuel so all of the mixture is burned and you get the most out of the cycle...
but once u put higher octane fuels in the system designed for lower octane fuels it has a harder time burning because its compression isnt creating enough heat to burn all of it when the spark plug ignites so a lot of excess fuel is dumped out but is filtered by the catalytic converter thats why you dont smell it but it still is getting dumped out...it makes your car run rich, and uses up more gas so you're actually getting less gas mileage out of your car...
Last edited by ragingSPAM; 11-01-2006 at 05:36 PM.
#65
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Rep Power: 0 well i put 89 octane when i first got my car but it ran like doo doo then i read the manual then it say should use 92 octane and bla bla bla like that so i been using it ever since and my car works great.
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Rep Power: 0 I'd give 89 a try again...
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Rep Power: 787 haha the manual says 87 in a civic, it will give the best mileage and performance. maybe you picked up the manual for dads s2k by mistake
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Rep Power: 238 yea where in the manual does it say use 92 octane... idk where your at but last time i checked the octane ratings are 87, 89, 91, 93, 97, 102, 108, 119 (which is ethanol based)
#69
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Rep Power: 0 The octane ratings you're used to are local. You can get other octane ratings here. Our standard 3 here in CO at most gas stations is 85, 87, 91. On the track I use 105.
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#75
Re: 89 octane = reduced mpg
From my experience, my ultimate test was to fill the tank several times with 87 octane and 93 octane on my previous Honda cars. 1997 Accord EX (4 cyl), 2008 Accord EX-L (4 cyl), 20011 Accord EX-L (4 cyl), 2009 Civic Coupe EX.
On every single one, testing miles per gallon and performance, I have gotten better mileage using the higher 93 octane.
Now whether or not my heavy foot has anything to do with it, is something to consider as well... I like starting off the line as quickly as possible to get up to speed limit.
Also, I have a friend that is qualified for working on the NSX, and he advised me all Honda cars are built for super, high octane. So I believe him after running my tests using the various octane to see how far I get for the money.
When I calculated the miles per gallon to price per gallon... I actually could SEE if I was losing money or not!!!
People, it is very simple to figure out by calculating your fuel usage.
Sample:
$2.00 per gallon for regular (87) ... say I filled tank after 217 miles. that's 22 mpg
$2.50 per gallon for super (93) ... say I filled tank after 257 miles, that's 27 mpg
40 mile difference 40/2.5= $16 , 40/2 = $20
I saved $4.00!!!! not a lot, but still a savings!!!! it adds up over time!!!
On every single one, testing miles per gallon and performance, I have gotten better mileage using the higher 93 octane.
Now whether or not my heavy foot has anything to do with it, is something to consider as well... I like starting off the line as quickly as possible to get up to speed limit.
Also, I have a friend that is qualified for working on the NSX, and he advised me all Honda cars are built for super, high octane. So I believe him after running my tests using the various octane to see how far I get for the money.
When I calculated the miles per gallon to price per gallon... I actually could SEE if I was losing money or not!!!
People, it is very simple to figure out by calculating your fuel usage.
Sample:
$2.00 per gallon for regular (87) ... say I filled tank after 217 miles. that's 22 mpg
$2.50 per gallon for super (93) ... say I filled tank after 257 miles, that's 27 mpg
40 mile difference 40/2.5= $16 , 40/2 = $20
I saved $4.00!!!! not a lot, but still a savings!!!! it adds up over time!!!
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