Gas... What Octain?

[FireFighterSI]

Hey guys... I just wanted to know what octain everyone has been running on thier 2k2's. I've been running 93 Octain, and it loves it. I only used the one tank of regular befor I switch over. I didn't really pay attention to the difference, but maybe you guys did.

Well let me know whats up, and I hope I'm not running my car too lean.

Loves the high grade stuff though!

OUT,
Smiley

[02TafWhtSi]

I have read and heard different things - dealer says any more than 86 is a waste while an article in one magazine or another said 91. I routinely pump her up with 89 to be on the safe side but every third fill-up I go with the 93 to be on the safe side:) .

[CleanBlackSi02]

I've been using 93, but then again I think everyone that likes their car does that. I'll have to do a full tank of lower octane gas sometime to see if there is a noticeable difference.

[xlr8]

ill never use anything, but premium, and full synthetic oil. thats the best thing about buying a car new, you know how its been taken care of

[2k2civicSi]

nothing but 93 goes in my tank

[fishboy]

91's all we have in CA. that's what i put in.

[IceD out N CALI]

I use 91 most of the time but sometimes regular cause gas prices really blow

[brianc593]

I fill up with 91 because thats the highest octane we have here. If we had 93 thats what I'd be using.

[SilverArrow]

I myself only have 91 octane out here and that's all I have used but I don't know what the dealersihp put in when they filled it up?

[punkdork]

I was stupid enough to try 87 since the manual only says 86 and up. I got some detonation. I'm on 89 and will switch to 92 and stick with it on my next tank.

[2002HatchSi]

i use 93 octane..... but gas prices suck in new orleans its like 1.73 a gallon here omg its crazy.... but my baby likes the good stuff so i take care of her....

[Brenetics]

Originally posted by punkdork
I was stupid enough to try 87 since the manual only says 86 and up. I got some detonation. I'm on 89 and will switch to 92 and stick with it on my next tank.

What exactly is detonation? What actually happens when it does occur?

I only use 93

[SpacemanSpiff]

I'll give this a try, If i'm wrong, someone let me know.
Detonation or pinging is when the fuel/air mixture in the cylinder detonates due to the compression in the cylinder and not the spark from the spark plug. This can cause damage to the engine.
Octane is a measurement of how resistant a gasoline is to detonation. So engines with higher compression ratios need higher octane to avoid detonation. The 9.8 to 1 compression ratio in the Si should be OK with 87, but the 11.0 to 1 compression ratio in RSX-S needs 91 or higher octane. Our engines do have knock sensors, so if the computer detects pinging it should retard the timing to prevent it. So you could run an RSX-S on 87 octane, it would just be a little down on power because the engine would adjust to the lower octane.
Some people feel that the Si and base RSX won't benefit from octane higher than 87 since that is what Honda designed it for, others can tell a difference. It's pretty much up to the individual, but I have been running 93 in my Si, haven't tried 87 yet.

An interesting note: Diesel engines operate on compression ignition, no spark plugs. So a diesel fuel is rated by its cetane rating, octaine is not used. The cetane rating tells how easy it is to ignite the fuel by compression.

[SpacemanSpiff]

vtec.net found when dyno testing an Si that it made more power with higher octane fuel.
link:
http://beta.vtec.net/articles/view-article?article_id=8542

[xlr8]

Originally posted by SpacemanSpiff
I'll give this a try, If i'm wrong, someone let me know.
Detonation or pinging is when the fuel/air mixture in the cylinder detonates due to the compression in the cylinder and not the spark from the spark plug. This can cause damage to the engine.
Octane is a measurement of how resistant a gasoline is to detonation. So engines with higher compression ratios need higher octane to avoid detonation. The 9.8 to 1 compression ratio in the Si should be OK with 87, but the 11.0 to 1 compression ratio in RSX-S needs 91 or higher octane. Our engines do have knock sensors, so if the computer detects pinging it should retard the timing to prevent it. So you could run an RSX-S on 87 octane, it would just be a little down on power because the engine would adjust to the lower octane.
Some people feel that the Si and base RSX won't benefit from octane higher than 87 since that is what Honda designed it for, others can tell a difference. It's pretty much up to the individual, but I have been running 93 in my Si, haven't tried 87 yet.

An interesting note: Diesel engines operate on compression ignition, no spark plugs. So a diesel fuel is rated by its cetane rating, octaine is not used. The cetane rating tells how easy it is to ignite the fuel by compression.
there is no need for correction here, you are exactly right

[02TafWhtSi]

but in the real world would I experience any performance benefit from switching from 89 to 93? I mean it would only cost an extra buck or two - is it worth it?

[punkdork]

Originally posted by 02TafWhtSi
but in the real world would I experience any performance benefit from switching from 89 to 93? I mean it would only cost an extra buck or two - is it worth it?

Whether or not the performance benefit is worth it is up to you. However, if you're experienceing detonation it is most certainly worth paying for the higher octane gas.

[02TafWhtSi]

I've filled her up w/ 89 4 times since i bought her and have not experienced detonation at all. So I guess I'll stick w/ it unless someone can convince me otherwise. I don't mind paying the diff. but the manual and dealer both said 87 and any higher would be a waste.

[HondaMan]

Hmmm...I guess I'm the minority here. I just run 87 in my ride, because past research told me that as long as you have no detonation or pinging you do not need a higher octane. I guess the engine computer does make up for it and in turn produces less horsepower. I think anything over 87 is over kill but I will fill up with 93 for my next tank of gas and report my findings here since nobody appears to have really started with 87.

[02TafWhtSi]

yeah let us know - I wouldmlike to see if there's REALLY any difference!;)

[Brenetics]

Thanks for the explanation Spiff!!

That link you gave sheds a lot of light on which octane to use.

[HondaMan]

Report: The results are finally in (I don't drive it a lot...just work and back mostly) on going from 87 octane to 92 octane, and I must admit my car runs better with 92 octane (it loves the good stuff). Overall performance is better! I'll keep running 92 octane, unless I'm running low on funds and have to run 87 or 89 octane...damn 92 octane isn't cheap here in Oregon...hehe. :)

[chenchao]

Yeah, I used 87 at first and I confirm hondaman's findings that premium gas makes worlds of a difference. the car pulls much stronger through all of the rpms. Definitly a good switch for better gas mileage too. Still don't think I'm getting the 28ish mpg that the window sticker claims.

[abstrack]

vegas gots 100... anyone got that where they live?? i wanna try that.. hehehe

[02TafWhtSi]

Originally posted by abstrack
vegas gots 100... anyone got that where they live?? i wanna try that.. hehehe

wow - thats almost like race gas. My father can get 104 octane from an airport by his house for his 66' Vette but I think thats going a little too far:) :rolleyes:

[grooveline]

I use preemo in my ride. I say if acura wants their rsx to have premium, and our cars have the engine of an rsx, then by all means, I will use premium.

Also, with all the i-vtec gadgetry, and hot compression, might as well get the cleanest burn possible.