Do and donts of petrol..

[Lord Derosso]

So we have all sorts of fancy names for petrol nowadays such as Techron95, Ultra95 etc etc. What is best for the average 4 cyclinder jap bike like my GXS600F? I was told just to use 95, which was my first idea anyway, but suspect that she may run better on different ones though I am not sure if petrol designed for lower reving car engines is better for the bike using the fancy named addatives. In the past I use to just get Super from the old BP and that was it for all my bikes, but its been a few years since I have been riding and I am not up to date with events. Accordingly, I would love any and many comments on what and why - the petrol you use for your pride and joy, or are you convinced that all petrol is equal?? Is there any one station in central Wellington any local would recommend? Sounds silly? If you live in the countryside some garages have old ground tanks and water etc in the fuel makes for a very sick bike...........

[sprocket]

Ha funny i was gonna post the exact question:second:

But i would like to add do you need to have your bike tuned for specific fuels?
ie: if you run 91 and switch to 98 i have heard of ocasions of bikes running like dogs? not so much fuel injected bikes more so carby bikes can someone pls spread some more light on the issue?

[Storm]

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?

[Edbear]

Your bike will run best on whichever fuel it's tuned to. My 'F' runs best on 91, I tried 95 but it didn't like it. I could tune for it, but it goes like stink as it is. Some with computer controlled injection may automatically remap the tuning for whichever fuel you put in it,as our Nissan Pulsar does and it runs noticeably better on higher octane. Not certain if this is true of bikes though, perhaps a techie can enlighten us on this.:scooter:

[sunhuntin]

did consider trying the 95/98 in scuffy....but the price shot too high to allow for an experiment that would likely fail! LOL.

[Bonez]

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 use 91 in the GB400, in fact in all my old girls, only GasAxe pings under load. All of them seem to reach there original specified top speeds/maximum ranges ok using 91:yes:. Don't see any point in paying extra for naff all.

Totally unscientific of course. But 91 "just works" for me.

Your Goose seemed to trot along ok on that Taupo run.

[Storm]

Thats cos I was in your slipstream. Personnaly I've never noticed any difference between 91 and 95, 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?

Also, theres always room for a bit more speed in the trotting dept

[Oakie]

When I bought my bike the mechanic at the shop told me to run it on 95 as '91' doesn't necessarily have a 91 octane rating. '91' is just like a trade name for a fuel of around about 91 but may be a little less. He said they put '95' in all their bikes.

[Bonez]

Thats cos I was in your slipstream. Personnaly I've never noticed any difference between 91 and 95, 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?

Also, theres always room for a bit more speed in the trotting deptWhat does the exhaust oulet look like running on 91 after a long ride?

[sprocket]

When I bought my bike the mechanic at the shop told me to run it on 95 as '91' doesn't necessarily have a 91 octane rating. '91' is just like a trade name for a fuel of around about 91 but may be a little less. He said they put '95' in all their bikes.

I have read that 96(95 now ) can have a lower octane rating than 91 for the simple facts that the aromatics in it are so unstable, so the fuel goes off faster so, I perfer 91 over 96, however 98 is imo a far more advanced, fuel its guarenteed min 97.5 from the pump, takes longer to go stale , is better for your engine , and well comming from a modified cage which ran on nothing but 98 I dont understand why you wouldn't use it ? I dont like it when ppl use cost as an excuse when it costs me over a hundy to fill my caldina on 98 surely $30 of 98 for a bike is very reasonable?

pls correct me if im wrong but most jap import bikes are already tuned to run a higher octane, are they not ? seeing as japan use 105 ron

Also i find ....well im my car anyway that i get better milage using 98 .

So is it not cheaper in the long run to retune your bike and reap the benefits over time?

Anyway what would a noob like me know ...Sheesh

[thealmightytaco]

Gotta run what the bikes made for; if it needs 91 then 95 might blow back cause it's taking too long to burn, and if it needs 95 and you run 91 then you'll overheat it and get detonation 'cause the well burnt gases are trapped in there too long.

WRX's are chronic for blowing the rear piston if you don't use 98 even, because that piston gets the last of the cooling water and always overheats.

[Storm]

What does the exhaust oulet look like running on 91 after a long ride?

Dunno, never looked. Its usual state is black soot around the arse end as far as I know

[sprocket]

WRX's are chronic for blowing the rear piston if you don't use 98 even, because that piston gets the last of the cooling water and always overheats.

Well actually its due to the poor setup in the fuel delivery system #4 leans cause its the last to get the supply hench why they go for a two rail setup when modified, lol i know cause ive dont it at meremere was an expensive lession

[VasalineWarrior]

We need Motu to add something onto this thread. Ive always gone for the ''more octane burns better=faster and better running bike'' so I justify the extra $2 this way.
Ran dirt bikes and the old cbr on 91'. Became pricks to start and idle lower.

[Titanium]

I run 98 ultimate, bike tunes for any gas I put in it but requires a minimum of 95 octane to run properly.

Also Higer octane burns slower and cooler not hotter and faster.

Peter

[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...:whocares:

[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:yes:

[Brett]

Without going into the chemistry of it, Octane (from the cane family) is a combustion compressant (SP?). I.e. the higher the octane rating, the harder it is to ignite.
As previously stated, incorrect or complete ignition of the fuel in the cylinders could allow the fuel to ignite from the outside of the cylinders inwards to the centre of the piston. WHen it all meets in the middle, it 'explodes' as opposed to a chamber filled with a higher octane fuel that combusts cleanly all at once.

I have a modified cage as well as the bike, and i have found that the cage runs best on 98, and the ZXR250c runs the same on 98 as it does on 96.
I have found (just two weekends ago) that using Mobil as a fuel i get considerably more mileage out of the cage (based on open road driving) than when using BP fuel.

I have also noticed that the bike runs better on NON BP fuels.

I can't believe that it cost me fricken $30 to fill the bike today...

[SPman]

GSXR 1000 - ran Gull 91 - ran fine.
The 750SP was partial to 98 at times though...