Octane 87 89 91 93 95 ???????
Member
Joined: Sep 2006
Posts: 291
From: G-Ville, Pa U.S.A
Higher compression requires higher octane fuel, or a later spark, to prevent detonation. Hence how higher compression engines can automatically cope with lower octane fuel by retarding ignition.
It says "87 or higher" because 87 is the minimum that Honda recommends running in the engine, because that's the fuel that was used for their performance ratings. It should be able to run on lower octane fuel, with the knock sensor detecting any knocking and retarding ignition as necessary, with decreased power output. The question is, can it advance the ignition when running on octanes higher than 87? That's the key. Without that, there would be no increase in power.
There's no question whether the engine will adapt to higher octane fuel, and there's no reason that it should take several tankfulls to notice a difference, if there is one. (Except for that confirmation bias that I mentioned earlier.)
It says "87 or higher" because 87 is the minimum that Honda recommends running in the engine, because that's the fuel that was used for their performance ratings. It should be able to run on lower octane fuel, with the knock sensor detecting any knocking and retarding ignition as necessary, with decreased power output. The question is, can it advance the ignition when running on octanes higher than 87? That's the key. Without that, there would be no increase in power.
There's no question whether the engine will adapt to higher octane fuel, and there's no reason that it should take several tankfulls to notice a difference, if there is one. (Except for that confirmation bias that I mentioned earlier.)
Member
Joined: Jun 2006
Posts: 1,710
From: The Twilight Zone
i was using 93 for a while and noticed alot of black residue in my exhaust pipe. And when i swapped out the plugs for IX ones i also noticed black spots around the base of all of the plugs. It seems to me that the higher octane was causing this because when i switched down the black residue disappeared from my exhaust. I use 89 now consistently and IMO it has proven to give the best overall performance/economy.
For the record, the Japanese Fit Owner's manual recommends both Regular and Hi-Octane gasoline. Japanese Hi-Oc is equivalent to US 93/94 octane and regular is about US 87. It's the same engine as here, so I would imagine the same recommendation applies.
Member
Joined: Mar 2007
Posts: 33
From: ca
What Type of GAS To GET????
I have my fit for 2mthn now and i been filling it up with premium gas at chevron. now someone told me that i don't need to do that because my fit isn't a v6 and it doesn't need that type of gas. therefore, they recommended the Regular, because Super would be a wasted of money, considering they are the same quality. I alway thought the premium was suppose to help you save gas and keep your car in good condition. If im wrong, then i would (gladly) switch to Regular/Super because i need to save some money. im very confuse and would like your guys opinion.
spec:
honda fit B
automatic
spec:
honda fit B
automatic
Member
Joined: Jun 2006
Posts: 1,104
From: Chattanooga
New Member
Joined: Apr 2007
Posts: 2
From: ND
I'm not TRYING to be a jerk here, but once again, you're talking about something you don't know about. Leaner mixtures produce more power. They are also more prone to knocking and create more pollution.
Stoichiometric air fuel ratio is 14.7 parts of air to 1 part of fuel. No common street car gets that lean (Honda Hybrids do it occasionally and beyond, going as lean as 23-1)
The closer you can get to stoichiometric, the more power you can get out of a given amount of fuel, so yes. You can get more power out a given amount of fuel because no gasoline powered cars that are commonly available today use all the power in the fuel we give them.
That was easy, so who is writing me my cheque for my millions?
Stoichiometric air fuel ratio is 14.7 parts of air to 1 part of fuel. No common street car gets that lean (Honda Hybrids do it occasionally and beyond, going as lean as 23-1)
The closer you can get to stoichiometric, the more power you can get out of a given amount of fuel, so yes. You can get more power out a given amount of fuel because no gasoline powered cars that are commonly available today use all the power in the fuel we give them.
That was easy, so who is writing me my cheque for my millions?
What does all that have to do with the Fit? It makes sense that the Honda engineers would understand the physics of their engines and program the computers appropriately. Using a higher octane may increase power some, but using lower than rated octane will decrease your power as the computer tries to compensate.
Member
Joined: Dec 2006
Posts: 514
From: Tromsø, Norway
Is the octan rating in Europe diffrent from US?
In the manual for my Jazz it recomend using 95 oktan.
We only have 95 and 98 oktan here in Norway...
Maybe that is the reason for the price being so high? About 1.95US$ / Litre of 95 Oktan (and a few cent higher for 98).
In the manual for my Jazz it recomend using 95 oktan.
We only have 95 and 98 oktan here in Norway...
Maybe that is the reason for the price being so high? About 1.95US$ / Litre of 95 Oktan (and a few cent higher for 98).
New Member
Joined: Apr 2007
Posts: 13
From: miami,fl
gas types
hello, Im trying to see if anybody is using 93 octane and if so .. is their a performance difference, also do you get better gas mialige ..or not.... the reson i ask is because ive read the manual and all it says is to use regular 87 fuel ...and i know the higher the octane the more performance so let me know please ..thanx
Member
Joined: Jun 2006
Posts: 1,104
From: Chattanooga
New Member
Joined: Oct 2006
Posts: 7
From: Tacoma, Washington
Save your wallet, please
Why is there so much obsession/hype/debate with premium? OMG premium! It is not a poor mans way of gaining HP on a car programmed for 87. On any regular old car, if there was any benefit (which there is not), it would be like 1 horsepower. You will build up more fuel deposits using too high of an octane. However, build up enough deposits and maybe you'll have that compression ratio you've always wanted 
.
You might as well go to Autozone, pick up some NOS Booster or Outlaw 104 and put it in your Pinto, cheaper way to acheive no results.
Unhooking your A/C would do more than using premium. That would have more realistic results in "power" and fuel economy because it reduces the parasitic load on the motor.
Give your car a reason to detonate, turbo, uber high compression, s/c etc... and then you can use 93.
.You might as well go to Autozone, pick up some NOS Booster or Outlaw 104 and put it in your Pinto, cheaper way to acheive no results.
Unhooking your A/C would do more than using premium. That would have more realistic results in "power" and fuel economy because it reduces the parasitic load on the motor.
Give your car a reason to detonate, turbo, uber high compression, s/c etc... and then you can use 93.
Member
Joined: Jul 2007
Posts: 20
From: NC
Gas type used for Fit?
I actually have a couple of questions. First is the octane rating. Here in NM, regular unleaded is 86 octane.....not 87 which is what's specified in the manual. Is this OK???
Also, which brand of gas are most people using for their Fits? The manual says to use gas with detergents. The only brands I know that use detergents are Shell, Chevron, Phillips 66, and Conoco. I'm not sure about the Circle K or the Giant or any of the "mom and pop" stores which are usually cheaper than the major brand names.
Oh by the way, my fit only has 100 miles on it.......will it matter if I just use the cheapest gas I can find?
Also, which brand of gas are most people using for their Fits? The manual says to use gas with detergents. The only brands I know that use detergents are Shell, Chevron, Phillips 66, and Conoco. I'm not sure about the Circle K or the Giant or any of the "mom and pop" stores which are usually cheaper than the major brand names.
Oh by the way, my fit only has 100 miles on it.......will it matter if I just use the cheapest gas I can find?
i think the manual is saying you don't need to add "special ingredients" into your gas tank. like those octane boosters, horsepower increasers, fuel system cleaners, that kinda stuff. as for stuff (like techron from chevron for example), just use whatever the gas comes with and don't worry about it.
Sippy loves the Chevron 87 octane. I put supreme in just to see if it made any difference and Sippy was pissed! Ran that tank out as fast as I could and put the 87 octane back in and Sippy was once again happy! So was I. Glad to know I could use the cheaper gas without a problem. The Ford Ranger had to have Supreme or if made too much noise under the hood.
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