98, 95, Or 91

[All]

I have a fuel injected '06 GSR. I'm just wondering whether it's really worth forking over the extra folding for 98 octane fuel. I'm fairly sure the bike has an O2 sensor and will adjust for knocking. This being the case, is there any advantage to 98 octane fuel?

Anyone have any opinions/knowledge on this?

[deanohit]

Can't help you with your question, but cool bike!

[All]

Can't help you with your question, but cool bike!Thanks man, I'm pretty pleased with it.

[Macstar]

My experience is that the extra cost of higher octane fuel balances out in the end cause you get better fuel economy. So I am for it - plus you may find your bike rides alot smoother with the higher octane fuel.

You could always put a tanks worth in and see for yourself...?!

[ManDownUnder]

Get a tank of each and ride it out. See how many kms per litre you get and take it from there.

The better your bike burns the fuel, the less you'll use, so the lower the litres/100km figure will be.

I did it on the RF a while back and she far prefers 91 (lower kms/litre) AND of course it saves me money becuase of the lower $/litre. It is worth investigating.

[Grub]

I don't know your bike so this is what happens with mine...

I have kept a record of every fill since I've owned the bike and can now confirm that there is about 1km/litre difference between 95 & 98. I have never used 91 because of potential bad performance and increased literage in the same way that there's a differenc between 95 & 98.

Stats for the 2000 CBR600F4 are
- 95 Octane = 17.93 km/L, Dist 313.84, $/Ltr $1.735, $/tank $30.37
- 98 Octane = 18.44 Km/L, Dist 322.68, $/Ltr $1.767, $/tank $30.91

So, on 98 I get 10km further on a tank and it costs me only 54c more. I get the benefit of more power, cleaner running the anti-foul properties of the higher octane. That has to be the best option.

Main tank (13.25litre) goes onto reserve at 274.7km. Reserve (2.25 L) will last 54.9kms - all dry at 329.6kms

[All]

I don't know your bike so this is what happens with mine...

I have kept a record of every fill since I've owned the bike and can now confirm that there is about 1km/litre difference between 95 & 98. I have never used 91 because of potential bad performance and increased literage in the same way that there's a differenc between 95 & 98.

Stats for the 2000 CBR600F4 are
- 95 Octane = 17.93 km/L, Dist 313.84, $/Ltr $1.735, $/tank $30.37
- 98 Octane = 18.44 Km/L, Dist 322.68, $/Ltr $1.767, $/tank $30.91

So, on 98 I get 10km further on a tank and it costs me only 54c more. I get the benefit of more power, cleaner running the anti-foul properties of the higher octane. That has to be the best option.

Main tank (13.25litre) goes onto reserve at 274.7km. Reserve (2.25 L) will last 54.9kms - all dry at 329.6kmsShit, man, you get some seriously good mileage.

The main reason I ask is because 98 seems to be significantly more expensive where I fill up.

[All]

Get a tank of each and ride it out. See how many kms per litre you get and take it from there.

The better your bike burns the fuel, the less you'll use, so the lower the litres/100km figure will be.

I did it on the RF a while back and she far prefers 91 (lower kms/litre) AND of course it saves me money becuase of the lower $/litre. It is worth investigating.Another thing I was thinking about is the health of the engine. It seems I'm constantly bombarded with rhetoric about how 98 is better for the motor.

[Grub]

The main reason I ask is because 98 seems to be significantly more expensive where I fill up.

Yes it is, but that's the point in a way, you also get better mileage from it. The average price difference between the two doesn't look as wide as it appears to be at the pump but that's just the math.

Because 98 is often hard to find, it's only been 32% of my fillups and some of those were a while ago when the price was much lower. By comparision, all the recent fillups have been 95 on long (700km) rides so that has bumped the average price for 95 way up.

[All]

Yes it is, but that's the point in a way, you also get better mileage from it. The average price difference between the two doesn't look as wide as it appears to be at the pump but that's just the math.

Because 98 is often hard to find, it's only been 32% of my fillups and some of those were a while ago when the price was much lower. By comparision, all the recent fillups have been 95 on long (700km) rides so that has bumped the average price for 95 way up.700km is a good effort. What do you ride?

[All]

OK, I'm an idiot.:drool:

I just noticed that what people ride is displayed on every post.

[NZsarge]

Seriously, stay away from 91, it's shite fuel end of story.
Run 98 if you can but don't worry if you have to use 95 every now and then, that's how I come at it anyway.........Stay away from 91 though....Seriously.

[What?]

Seriously, stay away from 91, it's shite fuel end of story.
Run 98 if you can but don't worry if you have to use 95 every now and then, that's how I come at it anyway.........Stay away from 91 though....Seriously.

Opinion based on what, exactly?
I own one bike that won't run at all well on 91 (and is not even keen on 95), another that runs best on 91, one that likes very high octane, and two that don't seem to be fussy at all as to what fuel I stick in them.
Best thing to do is run what the manufacturer recommends. Experiment as you will, but ten times out of nine you will find that the manufacturer did actually know what they were talking about.

[slowpoke]

Run the fuel that the manufacturer recommends, anything else is wasting money. There are a heap of variables involved especially on older bikes with worn carburettor components,or modified bikes, or servo's diluting petrol but a modern fuel injected bike in a good state of tune will run best on the recommended fuel. Running 98 rather than 95 will actually make the bike produce slightly less power due to slightly slower combustion. In effect you get a longer bang (98) rather than a shorter sharper bang.
The performance advantage with higher octane fuels comes from being able to advance the ignition timing and increase the compression ratio without running into pre-ignition (knocking/pinging/pinking) problems. Very few people go this far to be able to extract the performance potential.
If your bike doesn't run well on the recommended octane I'd change service stations rather than change fuels.

[TripleZee Dyno]

I have a fuel injected '06 GSR. I'm just wondering whether it's really worth forking over the extra folding for 98 octane fuel. I'm fairly sure the bike has an O2 sensor and will adjust for knocking. This being the case, is there any advantage to 98 octane fuel?

Anyone have any opinions/knowledge on this?
Pretty much what others have said, try them out and run the fuel that runs "the best"
Modern engines are pretty fuel tolerant and will run on just about any octane rating. Might run like crap but you will notice.
The O2 sensor is a mixture related device and doesnt have a big effect on detonation.
Just a point re manufacturers octane recomendations
NZ, Japan, Aussie, most of Europe use RON classification, ie 91 RON, 95 RON, 98 RON is what we see on our pumps.
The Americans, Canadians, and a few other countries use R+M/2 or PON
Basically RON is 4-5 higher than PON.
ie 91 PON is equvalent to 95 RON
If your users manual just says say 91 octane without specifying the classification it might pay to do a bit of research to be sure.
For instance Harley recommend 91 for most of their bikes but its 91 PON so over here the recommendation should be 95 (RON)
With bikes coming in from anywhere and everywhere who knows who your users manual was originally destined for?
Half the reason, I think anyway, that some bikes run better on 95/98 than the recommended 91 is because they are actually supposed to.
sounds like too much hard work!

[All]

The performance advantage with higher octane fuels comes from being able to advance the ignition timing and increase the compression ratio without running into pre-ignition (knocking/pinging/pinking) problems.Great point. I guess, to notice the advantage, you'd have to actively advance the timing and not just leave it stock.

[TripleZee Dyno]

Re Power
91 95 98 all contain pretty much the same "power" 98 isnt more "powerful" than 91
If it goes better, puts out more power etc with 98 then it means that the state of tune and engine design are designed for 98 rather than 91
Put 98 in an engine designed and tuned to run on 91 and you will lose power.
Put 91 in an engine designed and tuned to run on 98 and you will lose power.
You can equate losing power with losing efficiency, ie less mpg as well.
cheers

[All]

It's funny how many people recommend just recommend 98 across the board. The rationale must be that, because it's more expensive, it's better.

[Owl]

Cheers for the useful and informative information.:niceone:

[dipshit]

Great point. I guess, to notice the advantage, you'd have to actively advance the timing and not just leave it stock.

Even modifying your airbox to allow more airflow can create a leaner running engine. (efficient modern motorcycle engines are already running rather lean as they are) A lean engine runs hotter and is more likely to suffer from pre-ignition. This combined with crawling through traffic or riding hard on a tight twisty road on a hot summer's day, could run you into engine damaging pre-ignition.

98 will give you a greater safety margin than 91.

[dipshit]

Watch this vid comparing 95 against 98.

<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/NaPQLV5i4ks"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/NaPQLV5i4ks" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>

[All]

Watch this vid comparing 95 against 98.

<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/NaPQLV5i4ks"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/NaPQLV5i4ks" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>Wow, that was very interesting. I wonder if my bike can make use of the higher octane fuel.

[bimotabob]

That's pretty cool to get an extra 30Nm of torque on that fast car from the high octane fuel.
It will be able to sense detonation though, and make changes to the timing as required within it's powerful ECU.

Budget EFI cars never used to have knock sensors and I wonder if bikes do as they although they arent turboed
they are high performance.
Be good to hear a dyno report on a GSXR etc.

I have tried all the fuels on both my 2 stroke and 4 stroke bikes but cannot notice anything at all in milage or HP.

If you run on one type only you can always set your bike up to run best on it ay.

Regards

[dipshit]

Budget EFI cars never used to have knock sensors and I wonder if bikes do as they although they arent turboed they are high performance.


I know my SV hasn't got a knock sensor. What it does (and many other bikes) is to richen up the air/fuel mix under hard acceleration (i.e. load) to safeguard against pre-ignition.

Regardless, I still find it runs better on 98. Seems to pull harder from low revs with less engine noise and more of a deeper tone from the exhausts instead. Also get around 230ks from the 13L before the fuel light comes on instead of around 200ks with 95.

98 is just an overall better quality fuel, well worth another couple of dollars per tank over 95 in my book.

The 91 we get in New Zealand is utter crap.

[All]

I know my SV hasn't got a knock sensor. What it does (and many other bikes) is to richen up the air/fuel mix under hard acceleration (i.e. load) to safeguard against pre-ignition.

Regardless, I still find it runs better on 98. Seems to pull harder from low revs with less engine noise and more of a deeper tone from the exhausts instead. Also get around 230ks from the 13L before the fuel light comes on instead of around 200ks with 95.

98 is just an overall better quality fuel, well worth another couple of dollars per tank over 95 in my book.

The 91 we get in New Zealand is utter crap.Pretty decent mileage you get there. On my SV, I think I used to get about 120km per tank...

Mind you, that was mainly just town riding.