im using the good gas
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Member
Joined: Jun 2008
Posts: 239
From: Memphis
im using the good gas
since the recent drop in gas prices. ive decided to start putting silver or premium gas in my Fit. it is much more lively. and feels more responsive and overall feels like its getting a lil more power. damit i know my L15 is not fast but HOT DAMN is it fun 
Sorry dude. Test show, on the average engine, it doesn't improve mileage or longevity of the engine
Member
Joined: Sep 2006
Posts: 337
From: Denton, Texas
I paid $3.49 a gallon this morning. Whoo hoo!
Member
Joined: Jun 2008
Posts: 54
From: NL, Canada
Higher octane fuel requires less ignition advance. Ignition advance is controlled by the ECU. How else would you explain cars that take advantage of premium but can run on regular? Did you think the compression ratio was changing?
the debate of high octane vs low octane has been beaten to death but let me clarify what honda k series R series and L series do to deal with gas octane.
before we get to the car lets talk about the gasoline first
the octane number that you see is how hard the gasoline explodes a 100 octane will have a much more stronger explosion than 87. but it doesnt end there! it has a trade off, higher octane gas is not as flamable as a low octane meaning you need more time and pressure to get 100 to explode than what you need for 87.
with that clear lets move to the car. we all know that to make power you need a strong explosion in the cylinder but in order for you to benefit of lets say 100 octane you need to make sure that the engine can make the gas explode in the exact moment. so higher cylinder compression and ignition advance are needed/used.
please note that:
compression cannot be changed on the fly its set by the manufacturer or unless you change pistons, rings, gaskets
ignition can be changed on the fly IF the ECU allows it
on cars like the D series B series and ap1/2 F series ignition is set by honda and it does not move. thats why on a d series engine it doesnt benefit from putting 93 octane but on an s2k you will knock a lot if you dont put premium. these cars ECU's are preset for certain amount of ignition therefore requiring an specific octane rating.
this was kinda annoying for honda because for every country a car was sold in they had to create different ECU calibrations. due to the difference on octane from country to country
moving to the modern k series the R series and L series they made the ECU's for these cars that can change ignition on the fly. how it works is that the ECU its always advancing ignition +1 degree until it hears a knock. when it does hear a knock, ignition is retarded by 5 degrees. then the process is started all over again. this allows honda to use 1 map for all countries and at the same time optimizing performance regardless what octane is used.
the L series has a 10.4:1 compression therefore it will benefit from a little better octane rating in the gas because the ecu will advance ignition until it knocks
this should translate in about 3 more hp, nothing that you could feel that much. fuel econ should be up by a few mpg also.
so in conclusion is it worth it to put higher octane on the car? imo not really unless the price difference was under 5 cents between regular and premium i dont think its worth it to spend the extra 25/gal just to get 3 more hp and 1mpg...
before we get to the car lets talk about the gasoline first
the octane number that you see is how hard the gasoline explodes a 100 octane will have a much more stronger explosion than 87. but it doesnt end there! it has a trade off, higher octane gas is not as flamable as a low octane meaning you need more time and pressure to get 100 to explode than what you need for 87.
with that clear lets move to the car. we all know that to make power you need a strong explosion in the cylinder but in order for you to benefit of lets say 100 octane you need to make sure that the engine can make the gas explode in the exact moment. so higher cylinder compression and ignition advance are needed/used.
please note that:
compression cannot be changed on the fly its set by the manufacturer or unless you change pistons, rings, gaskets
ignition can be changed on the fly IF the ECU allows it
on cars like the D series B series and ap1/2 F series ignition is set by honda and it does not move. thats why on a d series engine it doesnt benefit from putting 93 octane but on an s2k you will knock a lot if you dont put premium. these cars ECU's are preset for certain amount of ignition therefore requiring an specific octane rating.
this was kinda annoying for honda because for every country a car was sold in they had to create different ECU calibrations. due to the difference on octane from country to country
moving to the modern k series the R series and L series they made the ECU's for these cars that can change ignition on the fly. how it works is that the ECU its always advancing ignition +1 degree until it hears a knock. when it does hear a knock, ignition is retarded by 5 degrees. then the process is started all over again. this allows honda to use 1 map for all countries and at the same time optimizing performance regardless what octane is used.
the L series has a 10.4:1 compression therefore it will benefit from a little better octane rating in the gas because the ecu will advance ignition until it knocks
this should translate in about 3 more hp, nothing that you could feel that much. fuel econ should be up by a few mpg also.
so in conclusion is it worth it to put higher octane on the car? imo not really unless the price difference was under 5 cents between regular and premium i dont think its worth it to spend the extra 25/gal just to get 3 more hp and 1mpg...
Last edited by wrussi; Aug 13, 2008 at 10:28 AM.
I also put mid-grade (silver) in my Fit. With my old car, I saw a significant improvement in mileage. In Europe, you don't even get gas with such a low octane rating - it usually starts at 91 octane, most cars need 95 or 98.
the higher the octane the more ignition advance you need.
New Member
Joined: Jan 2006
Posts: 19
From: Hyde Park, New York, U.S.A.
the debate of high octane vs low octane has been beaten to death but let me clarify what honda k series R series and L series do to deal with gas octane.
before we get to the car lets talk about the gasoline first
the octane number that you see is how hard the gasoline explodes a 100 octane will have a much more stronger explosion than 87. but it doesnt end there! it has a trade off, higher octane gas is not as flamable as a low octane meaning you need more time and pressure to get 100 to explode than what you need for 87.
with that clear lets move to the car. we all know that to make power you need a strong explosion in the cylinder but in order for you to benefit of lets say 100 octane you need to make sure that the engine can make the gas explode in the exact moment. so higher cylinder compression and ignition advance are needed/used.
please note that:
compression cannot be changed on the fly its set by the manufacturer or unless you change pistons, rings, gaskets
ignition can be changed on the fly IF the ECU allows it
on cars like the D series B series and ap1/2 F series ignition is set by honda and it does not move. thats why on a d series engine it doesnt benefit from putting 93 octane but on an s2k you will knock a lot if you dont put premium. these cars ECU's are preset for certain amount of ignition therefore requiring an specific octane rating.
this was kinda annoying for honda because for every country a car was sold in they had to create different ECU calibrations. due to the difference on octane from country to country
moving to the modern k series the R series and L series they made the ECU's for these cars that can change ignition on the fly. how it works is that the ECU its always advancing ignition +1 degree until it hears a knock. when it does hear a knock, ignition is retarded by 5 degrees. then the process is started all over again. this allows honda to use 1 map for all countries and at the same time optimizing performance regardless what octane is used.
the L series has a 10.4:1 compression therefore it will benefit from a little better octane rating in the gas because the ecu will advance ignition until it knocks
this should translate in about 3 more hp, nothing that you could feel that much. fuel econ should be up by a few mpg also.
so in conclusion is it worth it to put higher octane on the car? imo not really unless the price difference was under 5 cents between regular and premium i dont think its worth it to spend the extra 25/gal just to get 3 more hp and 1mpg...
before we get to the car lets talk about the gasoline first
the octane number that you see is how hard the gasoline explodes a 100 octane will have a much more stronger explosion than 87. but it doesnt end there! it has a trade off, higher octane gas is not as flamable as a low octane meaning you need more time and pressure to get 100 to explode than what you need for 87.
with that clear lets move to the car. we all know that to make power you need a strong explosion in the cylinder but in order for you to benefit of lets say 100 octane you need to make sure that the engine can make the gas explode in the exact moment. so higher cylinder compression and ignition advance are needed/used.
please note that:
compression cannot be changed on the fly its set by the manufacturer or unless you change pistons, rings, gaskets
ignition can be changed on the fly IF the ECU allows it
on cars like the D series B series and ap1/2 F series ignition is set by honda and it does not move. thats why on a d series engine it doesnt benefit from putting 93 octane but on an s2k you will knock a lot if you dont put premium. these cars ECU's are preset for certain amount of ignition therefore requiring an specific octane rating.
this was kinda annoying for honda because for every country a car was sold in they had to create different ECU calibrations. due to the difference on octane from country to country
moving to the modern k series the R series and L series they made the ECU's for these cars that can change ignition on the fly. how it works is that the ECU its always advancing ignition +1 degree until it hears a knock. when it does hear a knock, ignition is retarded by 5 degrees. then the process is started all over again. this allows honda to use 1 map for all countries and at the same time optimizing performance regardless what octane is used.
the L series has a 10.4:1 compression therefore it will benefit from a little better octane rating in the gas because the ecu will advance ignition until it knocks
this should translate in about 3 more hp, nothing that you could feel that much. fuel econ should be up by a few mpg also.
so in conclusion is it worth it to put higher octane on the car? imo not really unless the price difference was under 5 cents between regular and premium i dont think its worth it to spend the extra 25/gal just to get 3 more hp and 1mpg...
Member
Joined: Jun 2008
Posts: 54
From: NL, Canada
the debate of high octane vs low octane has been beaten to death but let me clarify what honda k series R series and L series do to deal with gas octane.
before we get to the car lets talk about the gasoline first
the octane number that you see is how hard the gasoline explodes a 100 octane will have a much more stronger explosion than 87. but it doesnt end there! it has a trade off, higher octane gas is not as flamable as a low octane meaning you need more time and pressure to get 100 to explode than what you need for 87.
with that clear lets move to the car. we all know that to make power you need a strong explosion in the cylinder but in order for you to benefit of lets say 100 octane you need to make sure that the engine can make the gas explode in the exact moment. so higher cylinder compression and ignition advance are needed/used.
please note that:
compression cannot be changed on the fly its set by the manufacturer or unless you change pistons, rings, gaskets
ignition can be changed on the fly IF the ECU allows it
on cars like the D series B series and ap1/2 F series ignition is set by honda and it does not move. thats why on a d series engine it doesnt benefit from putting 93 octane but on an s2k you will knock a lot if you dont put premium. these cars ECU's are preset for certain amount of ignition therefore requiring an specific octane rating.
this was kinda annoying for honda because for every country a car was sold in they had to create different ECU calibrations. due to the difference on octane from country to country
moving to the modern k series the R series and L series they made the ECU's for these cars that can change ignition on the fly. how it works is that the ECU its always advancing ignition +1 degree until it hears a knock. when it does hear a knock, ignition is retarded by 5 degrees. then the process is started all over again. this allows honda to use 1 map for all countries and at the same time optimizing performance regardless what octane is used.
the L series has a 10.4:1 compression therefore it will benefit from a little better octane rating in the gas because the ecu will advance ignition until it knocks
this should translate in about 3 more hp, nothing that you could feel that much. fuel econ should be up by a few mpg also.
so in conclusion is it worth it to put higher octane on the car? imo not really unless the price difference was under 5 cents between regular and premium i dont think its worth it to spend the extra 25/gal just to get 3 more hp and 1mpg...
before we get to the car lets talk about the gasoline first
the octane number that you see is how hard the gasoline explodes a 100 octane will have a much more stronger explosion than 87. but it doesnt end there! it has a trade off, higher octane gas is not as flamable as a low octane meaning you need more time and pressure to get 100 to explode than what you need for 87.
with that clear lets move to the car. we all know that to make power you need a strong explosion in the cylinder but in order for you to benefit of lets say 100 octane you need to make sure that the engine can make the gas explode in the exact moment. so higher cylinder compression and ignition advance are needed/used.
please note that:
compression cannot be changed on the fly its set by the manufacturer or unless you change pistons, rings, gaskets
ignition can be changed on the fly IF the ECU allows it
on cars like the D series B series and ap1/2 F series ignition is set by honda and it does not move. thats why on a d series engine it doesnt benefit from putting 93 octane but on an s2k you will knock a lot if you dont put premium. these cars ECU's are preset for certain amount of ignition therefore requiring an specific octane rating.
this was kinda annoying for honda because for every country a car was sold in they had to create different ECU calibrations. due to the difference on octane from country to country
moving to the modern k series the R series and L series they made the ECU's for these cars that can change ignition on the fly. how it works is that the ECU its always advancing ignition +1 degree until it hears a knock. when it does hear a knock, ignition is retarded by 5 degrees. then the process is started all over again. this allows honda to use 1 map for all countries and at the same time optimizing performance regardless what octane is used.
the L series has a 10.4:1 compression therefore it will benefit from a little better octane rating in the gas because the ecu will advance ignition until it knocks
this should translate in about 3 more hp, nothing that you could feel that much. fuel econ should be up by a few mpg also.
so in conclusion is it worth it to put higher octane on the car? imo not really unless the price difference was under 5 cents between regular and premium i dont think its worth it to spend the extra 25/gal just to get 3 more hp and 1mpg...
About gasoline, octane rating measures one thing and one thing only: resistance to detonation (knock, or compression ignition). Higher octane fuel does not explode more powerfully, it contains the same amount of energy as regular gas. It is possible to have a high octane fuel that contains less energy than a lower octane fuel (diesel vs. gasoline is a good example of this).
About ignition timing, advance refers to the number of degrees before top-dead center that ignition occurs. More advance is required for lower octane fuels as obviously the closer to TDC the greater the compression and the greater the chance of detonation. Conversely, higher octanes can run with less advance, as they can come closer to TDC without detonating.
About ECUs and ignition timing: Detonation is bad for an engine. If you've ever looked at the pistons and heads of an engine that's been knocking, you'll see tiny balls of metal stuck to them that were blown off the combustion chamber during detonation. To think that the engine in any modern car is constantly reducing advance until it hears detonation is laughable and a recipe for an unreliable engine (not something that Honda is known for).
That's not to say that knock sensors don't exist or that the ECU doesn't adjust ignition timing, it just works the opposite of what you seem to think. A modern car has a default ignition map designed for its recommended fuel. When the knock sensor detects detonation, ignition advance is increased until it goes away. This allows a car designed for premium to run regular when no premium is available (the original purpose behind the system). It has the added benefit of keeping a car from knocking if the compression ratio changes (say, from carbon deposits building up in the combustion chambers).
Finally, you can't tell from a compression ratio alone whether an engine would benefit from higher octane fuel. Displacement, combustion chamber shape, number of spark plugs per cylinder and bore:stroke ratio have almost as much effect on detonation as compression ratio. But the real trump card is whether the ECU is programmed by default to take advantage of the higher octane; in the case of the Fit it is not, or significant MPG gains could be realized just by switching to premium.
Last edited by Red Iron Crown; Aug 13, 2008 at 02:29 PM.
Member
Joined: Jun 2008
Posts: 54
From: NL, Canada
What kind of car was your old car? Was premium its recommended fuel?
Last edited by Red Iron Crown; Aug 13, 2008 at 02:29 PM.
Member
Joined: Jul 2008
Posts: 122
From: Lisbon, Maine, USA
Probably all just the placebo effect.
Actually you do, Europe uses a different scale... Same physical properties different units of measurement.
If we all listened to wrussi, then theoretically putting ethanol in your car would result in a huge increase in power and FE (because ethanol has a much higher octane).. which is definitely not the case... With out proper tuning and usually the use of a turbo charger, your HP will drop. Thanks red iron crown for correcting the mess..
If we all listened to wrussi, then theoretically putting ethanol in your car would result in a huge increase in power and FE (because ethanol has a much higher octane).. which is definitely not the case... With out proper tuning and usually the use of a turbo charger, your HP will drop. Thanks red iron crown for correcting the mess..
Last edited by boon4376; Aug 13, 2008 at 04:02 PM.