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Type of fuel?

Discussion in 'Bling and Appearance' started by pokiou, Nov 23, 2006.

  1. Hey guys what type of fuel do you guys use and what type of bike is it ???

    whats good a for a carbi 250 and so forth


    Thanks in advance.
  2. I use 95 octane in the zzr250 (1991 model), works well for me. Later model, large capacity bikes often prefer premium, 98 octane.
  3. best fuel = whatever the owners manual says to use.
  4. I've got a carby 250 four stroke (CBR250RR)

    I've been using mobiles middle premium thing, not the top of the range, and not regular - i think it's 98 octane, and that seems to work for me.

    at the moment i've got regular in it from an independant servo, just trying it out because another CBR250RR rider says he uses regular, but my idle so far seems to be uneven.

    BUT, i did run the tank dry to the bone for the first time since i've had it, and only put that reg fuel in it yesterday, so it could be some muck in the bottom of my tank.

    I'd say try 95 or 98 octane and see how that goes, seems to work for me.
  5. Do a forum search - you may get some more answers. I use regular unleaded and top it up with a little upper cylinder lube I carry around with me. Then again I have an '82 Triumph, not stock but not highly-strung, revving at 1 million revs or that fussy with fuels. Miss the good ol' Super though :)
  6. pokiou, any particular bike at all? what are you riding?
  7. I have a 1990 cbr250rr. I asked this question earlier and found it hard to get an answer except for some dumb pr*ck who told me unleaded was the best type of petrol for my bike, lol, thanks mate.

    I talked to 2 bike shops, and one shops said generally use plain unleaded, but every couple of tanks give it some premium to clean it out. Another shop said if i can use premium all the time, use it. So i tend to vary bewteen 91, 95 and 98 octane, what ever is available, easy and also how my financila position is makes up my mind, not that different fuel really makes much of a price dfference. i don't really notice very much difference between using the different fuels.

  8. No experience with bikes, but have experience with cars, and hey, if it's a fairly standard internal combustion engine, same rules should apply.

    Generally speaking - the higher the state of tune of the engine (normally to do with compression ratio - particularly related to boost levels on forced induction engines), the better grade of fuel you'll need to use.

    Wikipedia has a much better explanation than what I had just typed up and just deleted on the dangers or detonation and pre-ignition and this is the number one reason to run the appropriate fuel grade for your engine :wink:


    There is a comment specifically about motorbike engines in their article about Octane Ratings


    If your manufacturer recommends a higher grade fuel, run it as much as you can. Running a lower grade fuel will be ok as well - but I wouldn't be redlining it too often (or at all) until better quality fuel is back in the tank. Use the lower grade fuel only to get you to a place where you can reintroduce the good stuff.

    I've had to run my car (turbocharged - higher than standard boost - meant to run on 100 RON) on low grade fuel without octane boost on hot days (middle of summer), and as long as I kept her under say 5500rpm (max power @ 6400rpm) and did not put the engine under heavy load she ran fine.

    As for running a higher grade fuel than required - well - you're engine will be running probably a little bit richer than it should - but leaning out is what is dangerous. Personally I would only do this if say, I'd had the engine modified (or in a forced induction engine - the boost is turned up).

    I hope that helps, and if someone more technically inclined spots fault with what I have said, please butt in and say "erm, that's not entirely true" :wink:
  9. Might as well make use of the second post - to sum up for people who don't have enough time (or who couldn't be bothered) reading the Octane Rating article - here is a key paragraph from there:

    Though if your engine is prone to knock / ping on hotter days - a higher octane fuel could help.
  10. Which fuel to use in your bike??

    My bike has a digital fuel economy computer that works out how your bike is doing in Kms to the litre and also your average fuel consumption for the fuel you have in your tank. When I first bought my bike I used Premium 95 octain, because it was the only fuel I could get. The computer told me I was averaging around 16.5 kms to the litre. (The owners manual also tells you 95 octaine). Once I was able to put in the 98 octane, my fuel consumption went down dramatically to 22.5 kms to the litre.

    The 98 octane is better for your engine, it burns cleaner, and also gives you better power and economy. Although you will pay 10cents a litre more, if you do the sums, the 98 is actually cheaper to run.

    Good Luck
  11. I think the answer is generally different for every bike, and opinions and results may vary.

    But as the textbook rule of thumb goes, i've been taught that higher-octane fuel (eg 98) is best in higher compression engines, however, lower octane is better for lower compression.

    does anybody agree with this? or am i making a fool of myself?
  12. BP Ultimate seems to be the choice of champions here in QLD.
  13. Re: Which fuel to use in your bike??

    What kind of bike has that MC Mech?
  14. I asked the dealer when I bought my bike. He said to use the standard unleaded (I think its 91 RON at Shell) on my VTR250 after I asked him about using premium. My manual says 'unleaded' so anything from standard upwards is OK.
  15. Bah! Use what the manual states. Frankly, I'm a little surprised a motorcycle mechanic said to use the highest octane you can find, given that some engines, if not set up for it, can lose power through the slower burning nature of high octane fuels....octane merely denotes a fuel's resistance to detonation, not the "power content" of the fuel.
    Many bikes still do not have fuel injection, and of those that do, many don't have knock sensors or O2 sensors, so will not self adjust to teh different fuels. You might get lucky and notice a difference, or you might not. On a carbed engine, you WILL need changes in jetting and/or ignition timing to take full advantage of higher octane fuels.
    Neither my GTR or my Z (both 4 carb/4 cylinder engines) noticed a difference, either in economy, driveability or power output. So in the interests of saving my bike from burnt exhaust valves (slower burn of higher octane fuels means the exhaust gases can be significantly hotter), I use the standard unleaded specified for the bike.

    Regards, Andrew.
  16. Most bikes these days have very high compression anyway....... with your bike, you will be safe using 98.....
  17. Most bikes DO NOT have high compression these days, 9.0 is typically the maximum. Very few bikes are much over this.

    If anyone has a bike over 9.5 to 1, please put your hand up...........

    Regards, Andrew.
  18. Alot of 600's are around 12:1....
  19. 12.1:1 on my 600cc Fazer. 2001 R6 based motor.

    Run it on 95RON (primarily Caltex/Woolworths/safeway) as I find the BP pumps too high or the hoses too stiff or something :? (spilt fuel everytime I have used them). It seems to like Mobil 95RON too. Ran ok on standard unleaded once, but fill it up on 95 once it needed fuel again.

    A fellow Fazer rider on another forum, who races in the naked bike lite titles here in Aus, reported that the Fazer actually had less power on 98RON & 100RON as apposed to 95RON. Just an example to back up the "run what it was designed for rule". Bike has EFI btw.
  20. I don't have a manual, nor can I find one. (in english)

    I ride a 4 storke 4 carby.

    with 91 oc I am always switching to reserve on 200 km

    with 95 oc I am switching to reserve at about 240 - 250 km

    with 98 oc I switched to reserve at 260 as I was going through some twisty sections and didn't want to be losing power mid corner. then finsihing the ride and looking for a servo I kept going and going and hit 287 km before pulling into a servo. wasn't the right day to be testing my fuel consumption.

    Using BP ultimate I got the most milage yet. I'm willing to give it another go as soon as I empty out this current tank. I also noticed my engine seemed to cruise a lot "easier" while on the straights and generally wasn't working as hard. I guess the fuel was burning slower.

    No idea how that effects the internal bits. sparks, exhaust, carbys, etc.