What fuel do you use? BP Ultimate the worst performer !!

[ozzraptor]

I saw a program on tv where a test was run on some of the major fuels, standard and high octane , i always used bp ultimate 97% but now after seeing several separate tests i think i will go with shell v power 95% . The worst performer was bp ultimate which was very surprising , ony slightly better than standard 91 fuel, Shell V power rated the best with a 4 hp gain , same motor . That equates to roughly a 2hp gain on our bikes just for using a different fuel. Not that the average will really notice it unless your on the racetrack looking for every extra hp bit you can find.

[Spyke]

The octane rating, which down here is usually 91, 95, or 98, does not equate to the amount of energy in the fuel, it's how much compression the fuel can take before it goes bang - http://en.wikipedia.org/wiki/Octane_rating

Apparently the 95 here burns better than any of the 98s, so I run 95, and seem to get tens of kilometres further on a tank of 95 compared to running 98. Given that 95 is heaps cheaper than 98, and gets me further, I do my utmost to feed her that. I can't find the bookmarks that I thought I'd saved, but I have researched the topic before and some places did find more calories (or whatever) in 95, but again individual fuel suppliers can differ. Certainly in the case of petrol "more expensive" does not always mean "better", and it's worth trying 95 if you usually run 98, and vice versa. If I recall correctly the handbook suggests minimum 95 rating, so try a few tanks of 95 and report back? Just don't put any of those horrid E prefixed high-Ethanol fuels in, these old fuel systems are not designed for it.
Running 95 I frequently find that my 10 year old rap can leave dukes that are larger and younger looking rather sad, really pisses them off!

[pmogs]

V - POWER all the way for me , all bikes & performance car's ...

Just seem's to run better

[Spyke]

Wow, wish we had Shell servos in Perth, would like to try that stuff!

[OkBails]

Just my 2c...


Suzuki recommend using 91 in the TL1000s as its engine is less than 10:1 compression. Anything in the 8's or 9's and up to 10:1 run 91. Anything higher and money is being wasted. High compression engines usually start at around 10.5:1 compression and need the 95 and 98/100 is for engines up to 12.5:1. It's the higher compression (as Spyke says) that makes more power and thus requires higher octane fuel so it doesn't pre-ignite before 2 degrees after TDC.
If a high octane fuel is run in a low compression engine over a period of time the detergents in the fuel that don't get burnt off during detonation get past the rings and build up in the sump and turn the oil to sludge.
Oil companies have the right to add up to 5% ethanol in their non-ethanol fuel. Anymore than 5% and they have to brand it with the E prefix.
I used to cart fuel/LPG/crude oil around in tankers to servos and from oil fields to refineries and so had to sit in on a lot of presentations for training etc.
I run the Duke and the Rap on 91 with no issues at all. Every third tank put a fuel system cleaner additive in with your fuel and all will be good. Change oil regularly. Happy days.

[Anakist]

I use 98 in everything, Getting stuck in Monto with only 91 on offer meant it was a pretty hairy ride home with the two bikes (her Rap1000 and my 1125r) bucking and spitting like wild animals!
James

[norrie]

If the bike runs fine on the standard juice then that's what I use. My 1125 used to pink unless you put in the good stuff so that's what I used.

[OkBails]

I have to apologize to all forum members as I have been misled with some information regarding this issue. The TL1000s engine apparently has 11.3:1 compression. I was led to believe that it had 10:1 compression. I don't usually comment on things I'm unsure about and because I did comment on this I just wanted to do some research and make sure of the facts.
I will now be running 95 in the Rap once she's finished and on the road.
I will continue to run 91 in the Duke.
Sorry for this guys.

......I will be at the back of the classroom if anyone needs me...

[Spyke]

Thanks for the info Bails, I just had a look in the owners handbook and it does say the compression ratio is 11.3:1 but it only specifies unleaded fuel, no sign of a recommended octane rating. I also had a look at my Monster's owners manual and that does recommend 95 octane unleaded and its compression ratio is 10.7:1.

I thought it was only the 98's that had the detergents, do some of the 95s have them as well? Since I got a bad fill and having to clean everything out I've been aiming to run injector cleaner through every 5,000km or so, not sure if it does anything useful but it doesn't seem to do any harm.

[snapdragon]

Murco standard where I can get it - she seems to like it, or that V power stuff

[asdean]

Petrol is a big topic.
I think the best idea is to always use fresh fuel. I drain my tank after every ride and use it in the lawn mower or in the van, but I only ride once a month. I then fill up the night before a ride using a plastic gerry can as metal ones rust. I would also suggest going to a high volume service station with a good reputation and always try to use the same type of fuel and tune my bikes accordingly.
My personal preference is to use 95 octane, but as other members have suggested octane requirements are based on compression; but it is also based on ignition timing, and by compression it is effective compression rather than static compression, as excessive valve timing or overlap can significantly reduce static compression ratios. It is all about effective cylinder filling and spark timing, getting the balance right so that the max BMEP occurs around 5 degrees after TDC. If your bike detonates a higher octane fuel can help, as can reduced temperatures, removal of carbon deposits, and correct air/fuel ratios Detonation at peak torque is what destroys pistons, the odd rumble from being in too low a gear is a rider input not a fuel issue.
Fuels are more complicated now-days and a lot of 97 or 100 octane fuels have higher molecular weights and energy densities which require revised jetting and high energy electrical systems, which are designed for cars rather than bikes, using these fuels can result in black deposits forming on the spark plug. Shell pushed the higher energy density idea 10 years ago and a lot of dirt bikes had trouble.
I would also suggest staying away from any level of ethanol.
Any test or comparison of fuels measuring HP needs to be taken on your bike, not on some other bike or modern car with knock sensors, variable cam and ignition timing, and coil mounted spark plugs.
20 years ago I was a dyno operator and the biggest leveller or major improvement was always a new set of spark plugs, they always gave at least a 5% gain in HP.

It is very hard to tune your bike to operate at it's best as fuel is traded as a commodity and the same service station week to week may sell you fuel from bass strait in Victoria one week, then fuel from somewhere in the middle east containing heaps of sulfur the next.
If your bike is standard and runs on 91 octane without pinging, knocking or detonating, then spending money on anything above 91 is not required and may in-fact be detrimental.
It is too hard, so I buy the freshest 95 I can.
Thanks Al

[ozzraptor]

That's very informative Al, thanks for that, i am sticking with vpower 95 from now on. Must also do a spark plug change soon on the list of things to do.

[Spyke]

I'm always impressed by the depth and breadth of expertise on here, what an eclectic bunch you lot are!

[shebee]

I'm always impressed by the depth and breadth of expertise on here, what an eclectic bunch you lot are!

Nod nod what Spyke said! [emoji41]


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