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normal unlead or prem unlead?

Discussion in 'Bling and Appearance' started by spidie, May 20, 2008.

  1. i have a 91 CBR250RR and some say they could use prem unlead yet some says ONLY use the normal unlead.. but all of them did say to make sure its not the SHELL OPTIMAX...

    please clarify... thanks muchly...
  2. CBR250RR minimum fuel octane rating is 91 RON. I don't know if Australia is RON or MON or JOHN or what; I keep forgetting. Someone else can find out. ;)


    Using 91RON is good.

    Using <91RON will most likely result in engine damage.

    Using >91RON will result in little more than an excessively light wallet, but if there's no 91RON fuel available then 95 or 98 octane will be fine.

    Edit: Australia uses the RON scale. Our regular unleaded is 91 RON. Regular unleaded will be fine to use in the CBR250RR.
  3. I have been told by a bike mechanic NOT to use Shell Optimax ... although I don't think it's an issue any more, and that fuel is not available in Sydney any longer.
  4. Shell Optimax/Vpower can cause problems - all of which are clearly explained on the Vpower website.
    Not an issue with a CBR anyway, it'll run fine on standard unleaded (and higher octane fuels will not produce any extra hp).
  5. Hey spidie, have you heard of the search function?

    Also, where do you buy optimax these days??

    Premium versus standard must be the most commonly asked question on bike and car forums the world over.

    Basically, if you want to pay for the additives of the premium fuel, use it. Your bike wont get the benefit of the higher RON though.

    Puhleease lock this thread!
  6. I was told that Vpower is fine, whatever was the issue with Optimax has been addressed with Vpower.

    Why lock this thread? :?:
  7. spots.. in australia we are using RON
    i thought ron 91 was the least amount of octane we have?
  8. Your choice I guess to listen to whoever told you that - or the people who actually make the fuel.
    Link - click on the "is it right for my bike?" tab.
  9. Well I was told this by my bike mechanic ... a man of considerable experience and very good industry reputation.
    I looked at the Shell link, thanks, but I don't see any reference to the difference between Optimax and Vpower ... I'm lead to believe the problems with Optimax were more serious than that, and this is why they chnaged the 'formula' and changed name. Maybe there are other reasons, but if it's the same stuff why would you bother with the expensive rebranding?

    FWIW, I use Vpower all the time, nearly all of my bike's 11,000 km have been done on the stuff and it runs perfectly :) maybe it's OK for the bird but it effects other bikes.
  10. I knew 91 was our lowest octane, but wasn't sure if we were RON, MON or RON+MON/2.

    I looked it up myself out of boredom before anyone else commented, thus the self-edit in my post. :)
  11. No the problems with Optimax were exactly the same and related to the higher density of the fuel - it shouldn't cause any problems with a fuel-injected bike.
    There's naff all difference between Optimax and Vpower, they just (supposedly) added a friction modifier.
  12. From what I have heard most modern fuel injected bikes and cars can get something out of the 98+ RON Fuel (VPower) but that Carburetored vehicles should note use over 95 RON.
    Apparently the reason for this is along the lines that, The O2 detector in a new Fuel Injected vehicle means it adjusts the fuel/air mix to effectively use the fuel, but on a standard Carbie you end up running lean and thus damaging your engine.
    So Fuel Injected 95 – 98 Ron Carbie 91 – 95 Ron
  13. Depends what it was designed for. If it's meant to have 91 then you might get a slight advantage with 95, but 98 would be a waste.
    I've actually tested this with my car, mileage improves slightly with 95 RON but is actually slightly worse with 98. However later models designed for 95 (with a higher compression) do apparently benefit from running on 98 octane.
  14. And how! I drive a late model Alfa Romeo, and the difference in power is significant. Not only, but I get improved fuel economy as well, so all in all it costs me about the same to top up with high octane fuel.

    You know what? It used to be even better when I used to fill it with Optimax, that stuff was like rocket fuel ..... go figure :roll:
  15. St Rider, these fuel threads have been done to death, and especially the optimax parlaba. Hence the lock request. The thing is, noobs come in with half cocked thoughts and ideas and 3rd parthy hearsay about what mechanics think and the threads go on in all directions. Those members with a bit of cheekiness in their cereal that morning, lay traps and bait and troll for a bit of fun and stir up the pot. It's droll.

    Anyway, FWIW's I'm a vpower fan. I was an optimax fan too. I never experienced any issues since my 9R (carby bike) ran well on both fuels. There was a step improvement when Vpower came in. I reported as such on NR.

    All petrols will run richer (marginally to a little more) on straight carby bikes in winter due to the slightly different winter formulation. Higher RON non ethanol fuels tend to be higher density anyway, so directionally, run richer on carby bikes (not leaner FL) and even more so in winter.

    These days all the premiums are a much of a muchness and pass tier 1 requirements. The difference is down to the additives/snakeoil.

    Anyway, the point of this thread is about whether the Op's bike will blowup if he runs premium and the answer is no.
    He WONT harm his bike.
    He WONT get the benefit of the higher RON rating.
    He MIGHT get some benefit from the extra additives in premium that don't make it into the lower grade fuels.
    And since his bike is a 91RON bike, he can't run a lesser RON (which if he could, it might indeed cause problems).

    Falcon, where have you got your info from?? :? I CBF'd pulling it apart, but it has several factual errors.
  16. i use a 50:50 mix of diesel and LPG in my bike.
  17. I wasn't aware that there were documented problems with Optimax or Vpower or whatever the product is called now. Someone got a link?

    For a while I ran Optimax in both a CBR1000F and a EFI Blackbird to see if I could pick any performance or economy improvements.

    We then changed fuel card providers to Mobil and I use that product now.
  18. Well, I certainly don't recall this discussin but then again I'm relatively 'new' here. Sure you could have locked it, but them myself and others would not have learnt anything from it.

    I've been a member of a few forums over the years (motorcycling is not my only interest) and after a while much of it is the same recycled gooblygook. But it's news for newbies, and it helps them ... so what can you do?

    Ever watch the news or current affairs? Most of it is all the same regurgitated nonesense too.

    Is that so bad? I have never understood some moderator's insistence that the thread stay on topic. I always thought it was normal the way a thread evolves, after all that is the nature of dicussions generally, is it not?
  19. Not surprising with an Alfa, it's probably designed for 100RON but capable of running on 95 (or possibly 91). Not a 147 by any chance is it?
    My old carby Alfa is the same, designed for 100 but manually adjusting the ignition timing (which EFI can do automatically) allows it to run on 95 or 91. Of course doing that just makes it less fun to drive.
  20. No, it's a 156 JTS. It's not the fastest, but oh so much fun to drive. Once an alfista, always an alfista ...