octane rating

hey guys. i got my owner's manual in the mail today(i just bought my bike). i noticed it recommends anything above 86 octane. i thought most crotch rockets needed 93, am i wrong? should i go ahead and start putting 87 or 89 in it? sorry if this question seems elementary, but it surprised me that it only needs 86 or higher. thanks in advance! oh, and it's a 600rr.

That is true..the motor doesn't require more than standard grade fuel..but most people run the higher grade just because they can and the difference is probally .80 cents per fill up. Some motors require higher octane, but obviously that one doesn't..

ok cool, i think i'll keep putting 93 in until it cools down here in FL. i figure the higher grade fuel will have a better resistance against pinging in the high heat. but once it begins to cool down i'll step down the octane. thanks a lot for your help, limpz.

RT - my dealer actually suggested that I don't put the high octane in my bike.

they said it only calls for the lower octane and will not like the lower octane if you run high octane in it too often. once in a while is alright to clean things up.

ok, thanks man. guess i'll step it down on the next fill up.

quote:

ORIGINAL: Duke

RT - my dealer actually suggested that I don't put the high octane in my bike.

they said it only calls for the lower octane and will not like the lower octane if you run high octane in it too often. once in a while is alright to clean things up.

Your bike does not modify the ECU according to the fuel type/octane you use.

Rule of thumb is: If you have not rejetted your carbs, installed a full exhaust system, installed a Power Commander, or modified the air intake/exhaust in any way - It is a waste of money to purchase anything other than Regular/87 fuel.

I have to use Premium/93+ in my bike because I have modified it so much. If I am in a pinch and Premium is not available (in the sticks) then I can get by on Regular, but she does not like it. Pinging would not be an issue for me (since my timing has not been altered), just a loss of power due to incomplete combustion.

quote:

ORIGINAL: Baldman

quote:

ORIGINAL: Duke

RT - my dealer actually suggested that I don't put the high octane in my bike.

they said it only calls for the lower octane and will not like the lower octane if you run high octane in it too often. once in a while is alright to clean things up.

Your bike does not modify the ECU according to the fuel type/octane you use.

Rule of thumb is: If you have not rejetted your carbs, installed a full exhaust system, installed a Power Commander, or modified the air intake/exhaust in any way - It is a waste of money to purchase anything other than Regular/87 fuel.

I have to use Premium/93+ in my bike because I have modified it so much. If I am in a pinch and Premium is not available (in the sticks) then I can get by on Regular, but she does not like it. Pinging would not be an issue for me (since my timing has not been altered), just a loss of power due to incomplete combustion.

i didn't say anything about modifying the ECU.

i think your "rule of thumb" may be a bit whacked.
if the bike is supposed to run 93 octane, you should run 93 octane. same goes for cages, a lot of VW's for example.

We arent discussing cars, as this is a CBR forum. ALL CBR's only require 87 Octane. If we were discussing BMW moto's I would say Prem./93 MUST be used, as the manual dictates that.

p.s. How else would your bike know what octane you are using (by varying it) if your ECU didnt record/report it? That is what I read between the lines in your post. Since that was inaccurate, what are you infering?

Point taken Baldman. I was using the cages as an example.

I'm not sure if you are a really sarcastic person or not, as it is impossible to tell over the internet. But I just wanted to point out that most of your posts come across to me as being very in your face. I am in agreeance about adding humour to this forum, but balls out trying to make people feel stupid is not necessary.

Cheers.

Yes, I am a very sarcastic (in a humorous way) person (in person). Most people dont get me and often get offended. Often I am blunt and to the point - that is the only way I know to be when the facts are involved in a discussion. Sorry if I offended you. I am sure many will be offended by my posts...not that I am proud of that - just the way my type POV comes across.

p.s. ALWAYS pay attention to the smileys in my posts, as I try to convey my attitude with them (since my wording isnt always PC).

Wow -- it's hard to pick a more controversial subject. I don't know of anyone who's blown an engine using higher than recommended octane. My bike calls for 91 or better (1kRR).

Now I don't even claim to be an expert on octane but there are a couple of things I've picked up along the way. First is there are at least 3 different ways of measuring octane. Usually at the pump it's R+M/2 . R=research method. M= I dunno.

Second, and I actually do know this due to turbo issues, octane is simply a number placed on a fuel's ability to resist detonation. Detonation is when your fuel ignites before the spark. To say this is a bad thing is an understatement. Less than 2 seconds of detonation at high rpms can cause bent rods, dropped valves, holed pistons and generally a real crappy day. The only reason you'd need to run higher than recommended octane is if you've raised your compression. Shaved heads, turbo or NOS are a few examples.

Running higher octane in a 9:1 engine (93 as opposed to 87) will not increase horsepower. It will slightly decrease horsepower because the 93 resists burning more than the 87 therefore if you're not combusting at 100% efficiency some of the 93 will be unburned yielding less horsepower. It's not a lot less horsepower, but it is less.

And RE: Baldman -- his sarcastic tendencies are starting to grow on me. Plus he's in Jawja like me so he can't be that bad. ha ha. Since the written word does not convey body language or tone I'll just tell you dudes what I tell the wifey: If I say something that can be interpreted 2 ways and one of them is bad ... I meant the other one.

quote:

ORIGINAL: chainstretcher

And RE: Baldman -- his sarcastic tendencies are starting to grow on me. Plus he's in Jawja like me so he can't be that bad. ha ha. Since the written word does not convey body language or tone I'll just tell you dudes what I tell the wifey: If I say something that can be interpreted 2 ways and one of them is bad ... I meant the other one.

Yeup, this topic is one of the Black Holes, just like 'what type of oil is best'. Thus...I refuse to debate this topic and what I have learned along the way. I agree with most of what you said, except for your idea of what mods call for increased Octane (with cars that is a true statement - to a point).

I wholeheartedly agree with your last sentence! Time for a Group

just so you know... there are no hard feeling over here Baldman.

i just thought that for a newcomer to the forum, you were coming in guns-a-blazin.

but hey, if that is your style and you are as sarcastic as you say, we will get along just fine.

Oh my -- this is a group-huggin, hamster-sharin moment. I think I'll cry. Bwuhaahaaahaaa

Sorry, perhaps a wee bit too sarcastic?

Sounds like a Kodak moment....LOL....

Bwaaa -- it's all good dudes. A healthy debate on octane and how it affects your ride is a good thing. What turns peeps sour is when it gets to the "I have an engineer friend ..." stage. When my last bike (Busa) was stock, I couldn't run 87 octane even though that's what was in the manual. Peeps on the Busa boards said I was stoooooopid and the the Busa made more HP on 87. Well, I took what they said with a grain of salt because my particular ride knocked valves like a mofo when I used 87. And let me add that I used the 87 for several tanks before I gave up and started the 93 (87 knocked upon acceleration).

With the new 1kRR I just said screw it and run pure 93 baybee! She loves it!!! When the bike's happy, I'm happy!!

And if anyone wants the whole nine yards on octane, let me know. I've read and stored crap loads of info on the subject. The actual fact that matters most to me is how my bike runs. Period. Who cares about 1/2 horse at 15K rpms. That's all paper. The real world is what it's about.

1000rr huh, sweet. just got my 600rr a little while ago and it's fun. anyway, you should try running 87 just to see how it runs. i started out with 93 on my bike, but then thought i'd give 87 a try since it's what the manual recommended. it turns out that she runs fine on 87, so i just thought that since we both have modern hondas, maybe they could both run on similar gas. anyway, not trying to bust your balls or anything, just letting you know my results

Anyone notice a difference between gas stations? I can run 87 at some gas stations but if i go to chevron i have to use 91?

I havent really noticed a difference..and I get gas alot. I tend to un 91 octane all the time just because my bike is my baby and I want the best..even if it isnt required. Bikes dont hold enough fuel to warrant me buying the cheaper stuff..it might cost me a dollar more to use the good stuff. Now if my bike were a Suburban or something....87 ALL THE WAY!!!! (octane)Gas prices here in Californai is a out of hand!! 87 octane fuel is $2.25 a gallon for the cheap stuff around here

what do you mean? if you go to chevron, their 87 isn't any good? i haven't noticed any difference so far, but if i notice anything i'll let you know.

I think it is that tecron crap they add in to make it burn clean. I reworked the fuel system on my 76 cj5 and within a month I noticed a large build up of rubber in my filters. All I ran was chevron and it started eating away at my rubber hoses. Switched to shell ran fine. As far as running chevron 87 in my bike it knocks like crazy but if I go to shell I can run 87 just fine.

hey i was reading these posts about who's bike runs what octane and I actually looked it up in my owners manual and it says quote,
"Use of lower octane gasoline can cause persistant "pinging" or "spark knock"(a loud rapping noise) which, if severe, can lead to engine damage". Odd how other CBR's can run almost any octane and others have to run say 93. But it doesnt bother me any cause i was planning on putting 93 in mine. Is it just the newer bikes (2000+) that have to run higher octanes or are there earlier CBR that have to run higher octane?

Just curious?

-Tom-

The compression ratio of your bike will determine what octane you need. All octane rating means is resistance to detonation (pinging). At high revs and compression detonation will literally tear your engine apart. Rods that look like bananas are common.

Higher compression = more heat (Boyles Law), more heat = gas explodes in cylinder before spark (detonation), higher octane = resistance to heat induced detonation.

So, 11:1 or better in a high revving bike engine I recommend 93 -- if you're running NOS or a turbo then your compression will soar and you may have to run av-gas, water injection or an intercooler to keep things together.

R+M/2 . R=research method. M= I dunno.

The actual correlation is R+M/2, R=research octane, M=motor octane /2= add the 2 together and divide by 2 you get the PUMP octane