Fuel Change 91 to 98???

[2nd2last1]

Hey guys..

I searched for another thread like it but couldnt find one.
This might be a stupid question but dont wanna fu*k anything up.

Can I just chuck 98 on top of 91? or does the tank have to be emptied and done properly?

thnx

[Laxi]

Hey guys..

I searched for another thread like it but couldnt find one.
This might be a stupid question but dont wanna fu*k anything up.

Can I just chuck 98 on top of 91? or does the tank have to be emptied and done properly?

thnx

you should always keep your reserve tank full of 91, but fill your main tank with 98

[hayd3n]

you should always keep your reserve tank full of 91, but fill your main tank with 98

98 wont do any harm they even have little pamphlets at bp for the change
more bang for ur buck i reckon

[The Stranger:Me]

you should always keep your reserve tank full of 91, but fill your main tank with 98

Yeah, 91 doesn't go off as quick as 98. If you leave the 98 in the reserve tank it could be fucked when you do go to use it.

[LBD]

Hey guys..

I searched for another thread like it but couldnt find one.
This might be a stupid question but dont wanna fu*k anything up.

Can I just chuck 98 on top of 91? or does the tank have to be emptied and done properly?

thnx

91 to 98 might be to much of a step in one go....I would move up gradually...next fill go 2 Litres 98 and 8 Litres 91....following fill 4 Litres 98 and 6 Llitres 91...and so on....

Just having a lend of you....no problem changing....may even be an improvement....

[IdunBrokdItAgin]

91 to 98 might be to much of a step in one go....I would move up gradually...next fill go 2 Litres 98 and 8 Litres 91....following fill 4 Litres 98 and 6 Llitres 91...and so on....

Just having a lend of you....no problem changing....may even be an improvement....

You guys are taking the piss right?

More octane doesn't hurt unless the engine has been tuned to be retarded and can't handle it. The only problem I ever found was that if I put 98 in my bmw then it tried doing the same thing the engine was attempting to do - retarding the ignition. Nothing worse than a bit of temporary engine pinking occurred.

Higher octane generally can't hurt a lower (expecting) octane engine (unless it is miles apart but then we are talking back to the future and all that).

Apologies if I'm wrong but this is the first time I've heard half of this stuff (98 octane going off quicker etc). Just seems like a bit of a pisstake.

[Laxi]

my bike tends to pink a little on 91 but runs fine on 98, it's so slight that you hardly notice it, and my bikes 16yo

[LBD]

You guys are taking the piss right?

More octane doesn't hurt unless the engine has been tuned to be retarded and can't handle it. The only problem I ever found was that if I put 98 in my bmw then it tried doing the same thing the engine was attempting to do - retarding the ignition. Nothing worse than a bit of temporary engine pinking occurred.

Higher octane generally can't hurt a lower (expecting) octane engine (unless it is miles apart but then we are talking back to the future and all that).

Apologies if I'm wrong but this is the first time I've heard half of this stuff (98 octane going off quicker etc). Just seems like a bit of a pisstake.

Your on to it...no problem changing...and if the engine is designed for higher octane fuel it may well improve performance...Problems arise when you have an engine designed (Higher compression ratio) for higher octane fuels and run them on lower octane fuel...you will get a pre ingnition or pink....

[IdunBrokdItAgin]

I have heard however that 98 octane needs to be stored properly. Something about a fuel tank upgrade (warning stickers on side in case of crashes etc like the big fuel trucks which carry it).

[Laxi]

I have heard however that 98 octane needs to be stored properly. Something about a fuel tank upgrade (warning stickers on side in case of crashes etc like the big fuel trucks which carry it).

farrk mate it's 98 octane not nitro-methane
just as an interesting side note, lpg is rated 105 octane and is banned from jet boat racing in the us

[bsasuper]

98 octane is a good fuel, but I dont know where all the bp's are that sell it, premium is 95,96 octane, I prefer shell premium.

[CookMySock]

Pretty much you can mix and match fuel without consequence, unless your engine objects etc.

Usually, the higher octane fuels will be just a tiny bit more responsive, and you will get a slightly better km/L and therefore a better range.

Higher octane gas is more convenient for touring, where it can sometimes give you as much as an extra 50km range per tank of fuel.

I have never seen the cost/km comparison for 91 vs 95 vs 98, but my guess is it they would all be similar, perhaps with 98 being just a little more expensive to run.

Steve

[Pixie]

You guys are taking the piss right?

More octane doesn't hurt unless the engine has been tuned to be retarded and can't handle it. The only problem I ever found was that if I put 98 in my bmw then it tried doing the same thing the engine was attempting to do - retarding the ignition. Nothing worse than a bit of temporary engine pinking occurred.

Higher octane generally can't hurt a lower (expecting) octane engine (unless it is miles apart but then we are talking back to the future and all that).

Apologies if I'm wrong but this is the first time I've heard half of this stuff (98 octane going off quicker etc). Just seems like a bit of a pisstake.

Higher octane burns slower-potentially produces less power unless the compression ratio has been increased
Noobs

[meowmix]

You can put whatever you want in the tank, as long as it is above the miniumum limit to avoid pinging. Then going too high does give less power as per the previous post, but to a pretty small extent. My bike was tuned consertavely for a minimum octane of 87 CLC (91RON), and 98 actually made it run ever so slightly slower. 95 is perfect.
IIRC Octane is the measure of knock resistance, and the flame front speed is a side effect. You won't get better gas mileage on 98 unless you have an EFI bike that senses the octane of the fuel and advances the timing accordingly, or if it is a carb'd bike and it was tuned for that octane yeilding slightly more power per rev, so you use less throttle to get where yer going.

[2nd2last1]

you should always keep your reserve tank full of 91, but fill your main tank with 98

But isnt the reserve tank in the same tank just at a lower outlet for the fuel?

if ya no what I mean?

so you dont have to get the fuel tank flushed to get rid of the old 91?