high octane gasoline does it F&%K ur motor?!?!
Registered!!
iTrader: (3)
Joined: Jan 2003
Posts: 1,668
Likes: 0
From: Redmond, Washington, US
Rep Power: 0 
From what i've heard/read, the higher grades of fuel, don't have any different addatives.
I said this before briefly, but hopefully this will put this to rest.
Octane, is a measure of a fuels resistance to spontaneos ingnition, which is when the full ignites before it's supposed too (like on the upstroke...) Now, a lower grade of fuel will ignite at a lower temperature
Now for those of you who know your gas laws... PV=NRT or T=PV/NR, so when the pressure, or volume changes, the temperature will change. As the volume in the cylinder goes down, the temperature of the gas/air mixture increases.
Now on our civics, we have a 9.5/9.9 to 1 (dx,lx/ex, hx) ratio. 87 octane is fine for this, anything above will require higher fuel types. anything over 10.5 typically requires premium.
Lastly, our cars ECU's don't known instantly that you just tossed in some 105 "Race gas" they take several full tanks to fully adjust to the different type of gas. So... if you think you feel a difference just driving away from the gas station, it's just a "i spent 20 cents more per gallon" effect. I'm not saying that a higher octance won't benefit our engines, it's just that the gains probably aren't worth the extra money. If you're mpg increases by like 3, then it's still not worth the extra money.
With a higher octane rating, the ecu might advance or retard the iginition timing slightly, which could produce a little more power (very little) but, as stated earlier, this takes several gallons of gas running through your engine. Or if you reset your ecu.
Lastly, you're better off buying regular gas from a reputible gas station, then premium from some shitty corner pump. Gas is like oil... not all are the same. Some contain more water (yes water), sulpher and other contaiminents than others. I don't think i left anything out.... but it's 2 am and i'm going to sleep
I said this before briefly, but hopefully this will put this to rest.
Octane, is a measure of a fuels resistance to spontaneos ingnition, which is when the full ignites before it's supposed too (like on the upstroke...) Now, a lower grade of fuel will ignite at a lower temperature
Now for those of you who know your gas laws... PV=NRT or T=PV/NR, so when the pressure, or volume changes, the temperature will change. As the volume in the cylinder goes down, the temperature of the gas/air mixture increases.
Now on our civics, we have a 9.5/9.9 to 1 (dx,lx/ex, hx) ratio. 87 octane is fine for this, anything above will require higher fuel types. anything over 10.5 typically requires premium.
Lastly, our cars ECU's don't known instantly that you just tossed in some 105 "Race gas" they take several full tanks to fully adjust to the different type of gas. So... if you think you feel a difference just driving away from the gas station, it's just a "i spent 20 cents more per gallon" effect. I'm not saying that a higher octance won't benefit our engines, it's just that the gains probably aren't worth the extra money. If you're mpg increases by like 3, then it's still not worth the extra money.
With a higher octane rating, the ecu might advance or retard the iginition timing slightly, which could produce a little more power (very little) but, as stated earlier, this takes several gallons of gas running through your engine. Or if you reset your ecu.
Lastly, you're better off buying regular gas from a reputible gas station, then premium from some shitty corner pump. Gas is like oil... not all are the same. Some contain more water (yes water), sulpher and other contaiminents than others. I don't think i left anything out.... but it's 2 am and i'm going to sleep
Registered!!
iTrader: (5)
Joined: Dec 2001
Posts: 5,039
Likes: 0
From: Washington, DC
Rep Power: 348 
BTW, the 'lude needs 92, it's stated in the manual. Other than that you can put 87 in your Si with no problems. If you use anything higher, without having a high mileage engine (buildup) that pings, you will be wasting your money buying more expensive gas.
Registered!!
iTrader: (8)
Joined: Mar 2003
Posts: 3,024
Likes: 1
From: Zulu Alpha Tango Foxtrot
Rep Power: 312 Heh - this thread is hilarious.....
Most of the folks here who claim to have seen improvements in their driving habits on 93 octane have just fell for the clever marketing campaigns of the oil industry.
Yes - what has been said here about higher compression engines requiring higher octane fuels is correct. Our civic does not require it since the compression ratio is lower.
Higher octane fuels contain a longer hydrocarbon chain - thus when they burn they create more NOx and other environment polluting gases. Addtionally, using a higher octane fuel for a car that was not designed for one will not see any additional benefit - in fact, the higher octane fuel may actually foul your plugs, and wreak havoc on your O2 sensors because of additional carbon.
For the guy who stated that europe has 97 octane standard for their cars - RTFM. IE, Europe has a different standard on how octane is calculated than we do here in the US. Next time you go to the pump, look at the little yellow sticker which tells you what the octane rating is. Usually there will be a formula in small print under the rating. This is the method they use to determine the rating.
The main reason that most people think that 93 octane gas is better for your car is all due to the fact of ignorant consumers and shady oil companies. There really is no reason to call 93 octane fuel "premium." People see that and think, hey, if I pay more for it and its called "premium" than it HAS to be better, right? And if after reading this you still think that, than go back to the flock of sheep from where you came from, class dismissed.
Most of the folks here who claim to have seen improvements in their driving habits on 93 octane have just fell for the clever marketing campaigns of the oil industry.
Yes - what has been said here about higher compression engines requiring higher octane fuels is correct. Our civic does not require it since the compression ratio is lower.
Higher octane fuels contain a longer hydrocarbon chain - thus when they burn they create more NOx and other environment polluting gases. Addtionally, using a higher octane fuel for a car that was not designed for one will not see any additional benefit - in fact, the higher octane fuel may actually foul your plugs, and wreak havoc on your O2 sensors because of additional carbon.
For the guy who stated that europe has 97 octane standard for their cars - RTFM. IE, Europe has a different standard on how octane is calculated than we do here in the US. Next time you go to the pump, look at the little yellow sticker which tells you what the octane rating is. Usually there will be a formula in small print under the rating. This is the method they use to determine the rating.
The main reason that most people think that 93 octane gas is better for your car is all due to the fact of ignorant consumers and shady oil companies. There really is no reason to call 93 octane fuel "premium." People see that and think, hey, if I pay more for it and its called "premium" than it HAS to be better, right? And if after reading this you still think that, than go back to the flock of sheep from where you came from, class dismissed.
End Bringer
iTrader: (3)
Joined: Sep 2001
Posts: 6,254
Likes: 0
From: Fort Fatima, Florida, US
Rep Power: 0 from what i know, and what my text book tells me
higher octane does not mean cleaner
higher octane could mean better gas milage and better performance (read below)
octane ratings are there to tell you the gasoline's compression resistance, higher octane can withstand higher compression
the octane rating comes from (ron+mon)/2
ron is the research octane number
mon is the motor octane number
if you got fuel up north and try running it in somewhere with different temperture, it may affect your car's performance due to different gasoline blends, which leads to different volitility rates.
a few tips when you get gas:
1. do not get gas while the tanker is filling the station up, the tanker dumping fuel into the station will stir up dirt and sedements inside the station's tank, which leads to contaminats inside your tank
2. buy fuel from a busy station to ensure fresh fuel and less likely to be contaminated by water
3. try keeping your fuel tank around 1/4 full, running lower may cause your fuel pump to suck in water and other contaminats into your fuel line
4. do not overfill the tank, you may satuate your charcoal container
now, about my above statement in regards to the better performance and such...
quoting from my book [Prentice hall- Automotive Engine Performance by James D. Halderman]
"Do not purchasse fuel with a higher octane rating than necessary. try using premium high-octane fuel to check for operation difference. most newer engines are equiped with a detonation sensor that signals the vehicle computer to retard ignition timing when spark knock occurs. therefore, an operating difference may not be noticeable to the driver when using a low-octane fuel, except for decrease in power and fuel economy. in another words, the engine with a knock sensor will tend to operate knock free on regulae fuel, even if pemium, higher octane fuel is specified. using preium fuel may result in more power and greater fuel economy, howerver, would have to substantial to justify the incrase cost of higher octane fuel. some drivers find a good compermise by using midgrade fuel to benifit from the engine power and fuel economy gains without the cost of preium fuel all the time." [page 245 section 3]
edit: and about the topic of 100octane plus. i believe race gas contains lead, and our car's uses unleaded fuel, go figure...
higher octane does not mean cleaner
higher octane could mean better gas milage and better performance (read below)
octane ratings are there to tell you the gasoline's compression resistance, higher octane can withstand higher compression
the octane rating comes from (ron+mon)/2
ron is the research octane number
mon is the motor octane number
if you got fuel up north and try running it in somewhere with different temperture, it may affect your car's performance due to different gasoline blends, which leads to different volitility rates.
a few tips when you get gas:
1. do not get gas while the tanker is filling the station up, the tanker dumping fuel into the station will stir up dirt and sedements inside the station's tank, which leads to contaminats inside your tank
2. buy fuel from a busy station to ensure fresh fuel and less likely to be contaminated by water
3. try keeping your fuel tank around 1/4 full, running lower may cause your fuel pump to suck in water and other contaminats into your fuel line
4. do not overfill the tank, you may satuate your charcoal container
now, about my above statement in regards to the better performance and such...
quoting from my book [Prentice hall- Automotive Engine Performance by James D. Halderman]
"Do not purchasse fuel with a higher octane rating than necessary. try using premium high-octane fuel to check for operation difference. most newer engines are equiped with a detonation sensor that signals the vehicle computer to retard ignition timing when spark knock occurs. therefore, an operating difference may not be noticeable to the driver when using a low-octane fuel, except for decrease in power and fuel economy. in another words, the engine with a knock sensor will tend to operate knock free on regulae fuel, even if pemium, higher octane fuel is specified. using preium fuel may result in more power and greater fuel economy, howerver, would have to substantial to justify the incrase cost of higher octane fuel. some drivers find a good compermise by using midgrade fuel to benifit from the engine power and fuel economy gains without the cost of preium fuel all the time." [page 245 section 3]
edit: and about the topic of 100octane plus. i believe race gas contains lead, and our car's uses unleaded fuel, go figure...
Last edited by Voiceofid; Sep 29, 2003 at 04:00 PM.
Registered!!
iTrader: (1)
Joined: Jul 2002
Posts: 2,699
Likes: 0
From: Montreal, Quebec, Canada
Rep Power: 0 depending on the airplane there are different grades of fuel there is c-12 fuel which is for smaller airplanes and is rated aroud 120octane and then there one with kerosene (Sp?) mixture with some detter that runs 747 and bigger planes which is rated around 130.
Registered!!
Joined: Oct 2001
Posts: 1,225
Likes: 0
From: Tee Dot Ohh
Rep Power: 0 Originally posted by mclean987
ok everyone listen because i have done experiments with 2 cars with this both have i/h/e a 95 civic and a 2002 both sohc vtec anyway everytime i full up i reset mileage clock and check how many miles i get for the whole tank and on both cars 93 octane gives better gas mileage and on my 95 i have a ported and polished head and zex cam and all that **** and the car even sounds louder with 93 octance so this is what i use and i know everyone says its a waste but i can feel the difference and have tested it many times and i know that its worth the few extra cents because i get more mpg
oh yeah and airplance gas does make your car run much faster a friend of mine had a nissan sunny and he used to mix airplane gas with regular gas all the time because he had a link to get tons of it and it never ****ed up his car after running it for 5 years constantly and the car would be much faster and he only had intake
ok everyone listen because i have done experiments with 2 cars with this both have i/h/e a 95 civic and a 2002 both sohc vtec anyway everytime i full up i reset mileage clock and check how many miles i get for the whole tank and on both cars 93 octane gives better gas mileage and on my 95 i have a ported and polished head and zex cam and all that **** and the car even sounds louder with 93 octance so this is what i use and i know everyone says its a waste but i can feel the difference and have tested it many times and i know that its worth the few extra cents because i get more mpg
oh yeah and airplance gas does make your car run much faster a friend of mine had a nissan sunny and he used to mix airplane gas with regular gas all the time because he had a link to get tons of it and it never ****ed up his car after running it for 5 years constantly and the car would be much faster and he only had intake
Originally posted by Macko
What year and trim Sunny? cause some Sunny's have a freaking high NA powerband...
What year and trim Sunny? cause some Sunny's have a freaking high NA powerband...
Banned
Joined: Sep 2003
Posts: 265
Likes: 0
From: NY
Rep Power: 0 Originally posted by MagicRacing18
ONE: higher octain will not harm your engine. It wont do any thing better though, maybe run a tad cleaner, but nothing even worth it. And TWO: airplane fuel is not Kerosene, it just has several addatives that make it burn with less oxygen and what not. And yes, airplane fuel will harm you engine because of the addatives.
~nick~
ONE: higher octain will not harm your engine. It wont do any thing better though, maybe run a tad cleaner, but nothing even worth it. And TWO: airplane fuel is not Kerosene, it just has several addatives that make it burn with less oxygen and what not. And yes, airplane fuel will harm you engine because of the addatives.
~nick~
Registered!!
iTrader: (5)
Joined: Dec 2001
Posts: 5,039
Likes: 0
From: Washington, DC
Rep Power: 348
3. try keeping your fuel tank around 1/4 full, running lower may cause your fuel pump to suck in water and other contaminats into your fuel line
Registered!!
iTrader: (1)
Joined: Oct 2002
Posts: 2,150
Likes: 2
From: 4o8, California
Rep Power: 310 The only bad thing I've heard about running higher octane fuel is that it doesnt burn away as much like lower octane fuel does. This can be bad since the unburned fuel can collect in the catalytic converter, cooking it. FWIW
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
Supramk3
Mechanical Problems/Vehicle Issues and Fix-it Forum
1
May 11, 2015 07:55 PM
vtechcivic
Mechanical Problems/Vehicle Issues and Fix-it Forum
3
Apr 21, 2015 06:58 PM
answers to all these frickin turbo, nos, and super questions- im RANTING!!!!!!!!!! PLEASE READ!!!!!!
pinkytoe
General Automotive Discussion
31
Jan 8, 2002 06:05 PM
