95 compared to 98 octane

[bluezx14]

My bike pings it's arse off on 95, but it was tuned on 98. I don't know how that would affect it though as I don't have an ignition module?

[zx-10r]

I run the Eco friendly 95 from the local servo, I have noticed a 0% power increase/decrease.

I think the only way that 98 octane is going to help you go faster is by making your wallet lighter.

Having said that, perhaps if you have a programmable ECU you might be able to get better performance out of a higher octane fuel...

i dunno, i filled up with 98 again and it felt better. Accelerates a little faster down low and feels like it has a little morre power at 3000rmp~

Overall the feeling is it is running better

For this to be a valid comparison we need to know when your Bum Dyno was last calibrated....











........and have you ever heard of the placebo effect?

yes yes, the placebo effect, i was thinking it might have just been all in my head, EXCEPT that, i was running my bike on just 'premium' from any petrol station, so probably majority 95 octane, then i just went to a caltex and put in 98, not really thinking about it but when i got onto the road i was like, shit, this feel heaps better, got on gas harder and faster etc, so i wasnt really expecting any difference but there was.

Maybe just the way my bike was tuned with the PCIII ?

My point was i could tell the difference and just wonder what experience other people had, maybe my bike is just special.

[Gosling1]

.....My point was i could tell the difference and just wonder what experience other people had, maybe my bike is just special.....

No, your bike just responded to having a *better* fuel in it. Thats it. Thats why you should always run 98 octane as a matter of course.

Hell, I noticed the difference on a run to Qld years ago, riding one of my old zed 1000's. Now this bike was not 'jetted' to 91, or 95, or 98. It was jetted to run well on pump fuel....

Putting a tank of BP Gold into it at Hexham (just outside Newcastle) - and the difference was immediate and very noticeable. It simply accelerated better, and felt a great deal more responsive (crisp?) to small or large throttle inputs. Of course, this only lasted for 1 tank, and when I re-filled with normal unleaded, it went back to its standard response. There was no 're-jetting' requirted to get this improved response.....

IMVHO, I think all this stuff about tuning bikes to a particular 'octane' is a load of old cobblers. The only fuel that needs specific tuning alterations is methanol. Normal street bikes running on pump fuel simply don't require a tune-up to suit 'Vortex 98', instead of 'Mobil 95' or 'Shell Bats Piss E10' - whatever.

The variations in performance would be so miniscule as to barely register on any dyno - even Mick C's highly-tuned Bum Dyno !!

Bikes are tuned to respond with an a/f ratio that should be as close to 1:13 as possible (well, within the range 1:12 to 1:14) for normal everyday running. Not too rich, and not too lean. Sure, the technical arguments will follow about the stoichemetric ratio for low-octane fuels vs high-octane fuels.....its all a load of bullshit I reckon. A bike that is jetted 'correctly' and running well on one brand of fuel will still run well on another brand of fuel at a slightly lower or higher octane. The altitude where you live is far more of an issue !

[Stereo]

Perhaps your bike is running a bit rich to start with, putting a higher octane fuel in it could bring it back into the "butterzone".... Just a thought. I dont know enough about engines to know whether that is a valid point, Just know that mine didnt feel any different

[Mike]

I put 98 in my trackie this arvo, its off to be tuned tomorrow.

Only reason I went 98 is cause there was no 95. So it was 98 or Ethanol

[zx-10r]

yes throttle feels more crisp as you say.

[IsleofNinja]

My point was i could tell the difference and just wonder what experience other people had, maybe my bike is just special.

[/quote]


Considering the only major differennce between your bike and mine is the colour mate I would tend to say coincidence has a part to play here.
Personally I only run BP Ultimate in all my petrol vehicles same reason as I run squillion dollar V300 Motul esther syn oils , multi elecrode plugs and Gold GXWYZ!? chains etc etc !? Coz I'm ANAL about my bikes OK Do they make so much as a micky hair of difference ? ---- Not really

Yeah some days straight after a service / refuel it feels like it's carrying the front further / through more gears , feels snappier etc then others it feels to have lost it's edge a touch!? End of the day they all have a fairly primitive EFI comparitavely and do not compensate effectively for changes in ambient conditions .

Have run 95 in mine plenty of times and it doesn't seem to make a jot of difference , reason I run 98 is because it's 98 Ultimate or 91 ULP only here not too many options really !?

cheers

[stevespeedy]

91- 95-98 octane mmm it's not all the same !

Some years ago I owned a 71 Boss Mustang 12:1 compression and as the gov reduced the lead in fuel my car gradually ran rougher eventually I was mixing racing fuel to the fuel to make some difference
Then Shell (must have a thing going with the gov) started to sell a mix of unleaded (shell plus) fuel at higher price
And now we start with all the different octaine ratings and ethanol mixes!

Honestly I have found my 1996 F2 600 ZX6r Ninja is affected by the different fuels and the worst fuel is Shell the best fuel is BP Vortex as with the BP fuel I get excellent fuel economy and the engine feels very responsive were as by comparison the Shell fuel runs my tank out at 208k's and the rider response on the throttle is noticibly down by the way I would be sure as I use my bike as a daily comute and have tested the fuel theory more than once.
My opinion
BP Vortex excellent well worth the extra
BP fuels
Mobil
Burmah Ethanol not real bad although not every tank probably 1 ethanol to 4 unleaded
I dont like to use Shell at all

If you arnt scratching or scaping it your not riding it hard enought, keep it shiney side up

[corvus2606]

I gotta say, and this is comparing 1 tank of each on a new bike.

first run, i took the bike out on standard 91 (that was what was in the tank when i bought it). The bike felt amazing(because it was twice the size of the gpx) but it was pinging a little, so next tank, i went to bp and filled up on their 95. instant improvement, not kidding, i could tell when the old fuel was out of my lines, the bike quietened down, it was more responsive on the throttle, and felt smoother in general, I daresay if i was to go to 98, it would probably not run so well, the manual says 95, 95 seems to be the 'butterzone' performance wise, and I got about 15km extra out of the tank.

im no expert on mechanics, but i know when my bike feels like its running well, and BP 95 is where its at

[Strika]

I always run mine on that really good stuff...91! It don't fucking matter what fuel I run...I'm still slow!

in what parrallel universe are u slow???!!!

i call BS

Ask ANY national A or even B grader who has raced against me mate....and I am positive that they will gaurantee you, that I am slow!!!!!!!! Maybe I am a little faster than some road riders, but mate, in the overall scheme of things...trust me.....I AM SLOW!

[IsleofNinja]

Ask ANY national A or even B grader who has raced against me mate....and I am positive that they will guarantee you, that I am slow!!!!!!!! Maybe I am a little faster than some road riders, but mate, in the overall scheme of things...trust me.....I AM SLOW!

[Tests conducted on a road registered KLR250 race prapared by Marty himself including such major modifications including Dunlop trials tyres and handlebar tassles ..

Comparisons conducted under controlled conditions on a racetrack by proffesional riders and should not be attempted by others ]