Do and donts of petrol..

[imdying]

Ive always gone for the ''more octane burns better=faster and better running bike'' so I justify the extra $2 this way.

More octane burns 'worse' or slower, can't justify it that way. Best thing to do is use the octane rated for the bike.

Japan uses 100 octane, a lot of places have 105 also

[Lord Derosso]

My original question though refers to this:


SINCE I AM RUNNING 95

Which of the big companies is the best to use for a 600 cruising at 6000 to 8000 revs? And does any of the additional bullshit stuff cause problems. I think we need advice from the big four boyes and girles on this one. As for singles, great bikes and still 95 I believe though the old 'SUPER' was only 91 ?? Going back some years now. I think there use to be a 86 as well but this is in the days of high lead of course. I use to fill up heaps of taxis on LPG every night once too !!

[Pixie]

altough I run some 98 if I'm feeling rich on the basis that it'll burn hotter and clean out the built up scunge. Is this true or did someone give me the wrong idea?

You're wrong there bud,
91 burns hottest and fastest.
The anti knock properties of higher octane fuels is due to their slower burning rates

[Pixie]

My original question though refers to this:


SINCE I AM RUNNING 95

Which of the big companies is the best to use for a 600 cruising at 6000 to 8000 revs? And does any of the additional bullshit stuff cause problems. I think we need advice from the big four boyes and girles on this one. As for singles, great bikes and still 95 I believe though the old 'SUPER' was only 91 ?? Going back some years now. I think there use to be a 86 as well but this is in the days of high lead of course. I use to fill up heaps of taxis on LPG every night once too !!

I've got the answers from the "big four":
Mobil: ours is best
BP: ours is best
shell: ours is best
caltex: ours is best

Personally I find Gull is good as it isn't made from crap at Marsden point

[Lord Derosso]

The gal in Texas ?

[ZeroIndex]

In South Africa, there was 93 unleaded, and 97 leaded (and my car used leaded petrol).. My GF170 seems to prefer 95 over 91 (which is still less than $15 from reserve to full tank, and that gets me about 240kms)

[Stevo]

I run 91 in the 2000 CBR600F4. Tried 98 one day out of curiosity to see if mileage was better or anything. Well it bogged at low revs, but sounded quite nice when fanging it through corners higher in the rev range. Maybe I should try 95. (somewhere in between perhaps).

Incidentally I got identical mileage from the 98 as what I normally do on a long trip with 91, so I concluded it wasn't worth it.

[anoeldcx]

On another note, what sort of fuel would be the go for a small single?
(Not everyone has a massive gixxer/ kawa/yammie/honda firebreathing 1000cc y'know)
Is it related to compression ratio or what?

I ride a 2002 XR200R offroad in hill country most days (Yep, not a bad way to earn a crust) and it definitely prefers the higher octane. She will pink under heavy load and miss at high revs, especially when feathering the throttle, when using 91. Runs like a demon on higher octane! Honda dealer recommended higher octane also.

[What?]

I ride a 2002 XR200R offroad in hill country most days (Yep, not a bad way to earn a crust) and it definitely prefers the higher octane. She will pink under heavy load and miss at high revs, especially when feathering the throttle, when using 91. Runs like a demon on higher octane! Honda dealer recommended higher octane also.

My 83 XR200 is the same - runs like a bag of shit on 91, but goes hard on 96.
But then my F650 only drinks 91, and my CB1100 has a definite preference for 98.
Ya gotta feed them what they like, not what you like.

And Mobil vs Shell vs Caltex vs BP - there is NO difference. It's all the same stuff, with their own brand of detergent added (which is more than likely the same stuff with different names)

[Lou Girardin]

The only engines that adjust ign maps according to fuel used are those with knock sensors, which excludes most Jap cars.
I found that the Bandit doesn't like 95, runs best on 91 which is what a lot of bike engines are designed for.

[ZeroIndex]

I've got the answers from the "big four":
Mobil: ours is best
BP: ours is best
shell: ours is best
caltex: ours is best

Personally I find Gull is good as it isn't made from crap at Marsden point

..and gull in Hamilton, even though eftpos only, is generally 4 cents cheaper per litre..

[Drunken Monkey]

The only engines that adjust ign maps according to fuel used are those with knock sensors, which excludes most Jap cars.

I think you're mistaken there. At some rev ranges they (Japanese cars) will run open loop, but I've even had an '86 Toyota with knock sensors (I know this from an Error code 53 I got => I found the knock sensor had come loose, a common problem on several different types of Toyota).

Just throw in "knock sensor" then Toyota or Subaru or Mitsubishi or Honda into google = each one comes up with over 200,000 matches, on the first page you will find agents selling knock sensors for these vehicles.

Jap Bikes, on the other hand, are a different story.

[inlinefour]

My more modern bikes, 04/05 are designed to run on 91, according to the dealers and manufacterers. The 2-smokers I have can run on 91 as they of course have the oil attitive. As for the final older 4stroke? I still run it on 91 and it runs great. It was my understanding that older motors needed the lead in the fuel, irrelevant of octane rating? I dunno, as I'm no chemical engineer, but the proof is in the pudding and all my bikes run perfectly on 91. Personaslly I wonder if the need for higher octane fuels is bollocks, as if I want to go faster, then I get a bigger/faster bike...

[Motu]

The only engines that adjust ign maps according to fuel used are those with knock sensors, which excludes most Jap cars.
.

That's exactly what I thought when I saw the knock sensor code on a 300ZX twin turbo last week - there's no way they could fit a knock sensor in there,all space completely used up.The customer thought we'd pretend the knock sensor didn't exist either when I told him it'd take 8 hrs to replace it.

[sprocket]

Ok i have done some reshearch on this topic and have come up whit some intresting facts

firstly lower octane:

If the fuel is too lower octane, it may spontaneously ignite before the spark plug fires due to thermal rises from the heat of compression or from hot spots in the cylinder itself. (preignition as opposed to knocking)

preignition is the killer of all engines


High octane:

A high octane rating ensures that it takes a REALLY hot ignition source to ignite the fuel (such as a spark plug or the flame-front itself) and not just the rise in pressure & temperature that's a result of normal combustion. Note that the thermal rises in the cylinder are in direct proportion to the compression ratio of the engine

So....The higher the compression ratio, the higher the octane of the fuel that's needed.

pretty simple when you look at it like this