Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

What kind of petrol is best?

Discussion in 'Maintenance and Servicing' started by nakedninja88, Sep 8, 2015.

  1. Hay everyone :)

    When my z300 was delivered the dealer mentioned that 98 octane fuel is bad for the bike due to additives. He suggested to use 95 octane only.

    Is this true?
    Which level of octane is best?
    Will 98 octane really have bad effects?

    Thanks! Happy riding :)
  2. I'd use what the manufacturer recommends - usually the dealer will be correct, but check the user manual.
    • Agree Agree x 2
  3. modern fuel injected bikes alter the timing to suit the fuel, try both to find which gives the best power. you should only really watch out for ethanol fuel.
    neither cause short term problems, so if you find yourself running out of fuel and can only fill up with 95 but need 98 then 95 will work, vise versa is also true
    • Agree Agree x 2
  4. Shell Optimax use to get a bad rap due to plug fouling however I can't recall people having any trouble with V-power.
    95 seems appropriate, wouldn't waste my money going any higher unless you get it tuned for 98.
  5. I'm no expert but as far as I know the additives in 98 octane fuel will keep your engine cleaner. So for a brand new engine I say that's the best fuel to use. From my understanding the myth behind "Fuel with cleaning additives are bad"is true only if you have an older machine where the accumulated carbon deposits play a role to keep the vales and stuff clearances correct. If you suddenly get rid of all the carbon deposits in an older engine it might end up loosing compression.

    So in your case I would say use 98 octane. I particularly use BP 98 octane fuel which is advertised to have additives that will keep your engine clean. I ride a MT-09 and I ride every day. So far I have done 8k and the bike runs smooth.

    This is just my 2 cents and I might be totally wrong. If I were you I would wait for the experts to comment on this before taking a decision.
    • Agree Agree x 1
    • Disagree Disagree x 1
  6. Premium fuels do have cleaning additives in them however its debatable if it has any real effect, putting half a bottle of fuel system cleaner would be many times more powerful than the trace additives in the fuel. Most of the additives are placebo's. Can't see any reason not for cleaning the fuel system on older bikes, if anything removing the crud off inlet valves would be a good thing. Possibly you might upset some debris and block a carb jet.

    On older bikes (carbs) putting anything higher than what its designed for (ie 91) will offer no more power as the engine cannot advance the timings. Unless your getting detonation or knocking your best sticking to recommended fuel. Putting at least 95 is advisable if your 91 fuel is laced with Ethanol which damage the carbs and fuel lines on older bikes.
  7. This comes up all the time and sometimes there is a fair bit of wrong info.

    If you need 98 don't use less, use 95 unless you can get away with 91 then use that. Use the lowest you need.


    Your owner's handbook will tell you what you need.

    If you get caught short somewhere that doesn't sell what you need, don't panic. A short run on the wrong octane rating probably won't hurt much.
    Needlessly using higher is not better and for some bikes may be worse.
    • Agree Agree x 5
  8. I like Super from 1975,its a bit hard to get these days
    • Funny Funny x 3
    • Like Like x 2
  9. Lower octane rated fuel (91) could be bad for higher compression engines. If a high compression engine runs a low octane fuel it can cause the engine to detonate. This can cause engine damage due to the fuel detonating before the piston reaches TDC.
    When we used to have SUPER fuel. (I know I'm showing my age now) it was 100 octane and could be used in high compression engines. When petrol stations started dropping the octane rating on their fuels it caused a lot of problems for some high performance engine, as was mentioned "pinging", and worse case bent push rods etc.
    Anyway as has been advised use the octane rating recommended by the manufacturer. If you do need to fuel up with a lower octane fuel just keep the riding tame.
  10. Ha ha just got your post as I was typing mine yeah that was the stuff.
  11. When I picked my bike up from the dealer I got the same no 98 speil, but it was explained to me that as I was using the bike to commute the engine wouldn't get hot enough to burn all the additives so would lead to fouling.

    Interestingly the manual says that the bike is good on 91 but the dealer recommended 95...
  12. If the manufacturer says 91 is fine, I wouldn't be paying the extra for 95.
    • Agree Agree x 4
  13. #13 Markus_15, Sep 8, 2015
    Last edited by a moderator: Sep 9, 2015
    The fuel cap on my Kwaka says 95 so I stick to 95. Not sure if it is perhaps kawasaki thing only? I do on occasions use 98.

    Hey just checker z300 on bikepoint and RON95 is recommended. See 2015 Kawasaki Z300 ABS
  14. Liquid stuff. Coal clogs the filter.
    • Funny Funny x 2
  15. I switched to a new bike back in January and out of sheer habit i was using 95 until last month, when I read in the manual that I was supposed to be running 91. (Daytona 675 to a Street Triple RX. Same engine, just tuned differently). After changing to the manufacturer's spec it actually ran a bit smoother and my fuel economy improved by 10%. I sure didn't expect that much of an improvement!
    • Like Like x 1
    • Agree Agree x 1
  16. Well dude, I read through my manual for my ZZR250 and it says on there use a fuel with an equal to or higher research octane number 91...

    So if that helps you I don't know, I would check your manual specifically, or ask a kawasaki mechanic...

    I know it's a different engine, but when I owned a 2T scooter, the mechanic said to me not to use 98 or 95 because it cooked the spark plugs, so I only ever used 91, but according to what you can read on the fuel specs, really the additives create a cleaner more combustable fuel. I dont know I'm no mechanic, hope this helps though!
  17. image.
  18. #18 oldcorollas, Sep 9, 2015
    Last edited: Sep 9, 2015
    I wonder how many motorcycle salesmen have an understanding of science? :D

    edit: then again, there's not much of a jobs market for Scientists in Australia :( they might all be motorcycle salespeople by now...
    • Like Like x 1
    • Funny Funny x 1
  19. Ah it's not that they are just experts in science but each bike you look at they have a story to tell you and somehow they happen to have one just like that at home, of course it is an excellent bike. Went to buy a vacuum cleaner few months ago and the "good guys" had one just like I was after at home. The same with the dude in the sneakers joint, seemed to happen to have exact shoes I was looking for. Wow what a f*ng miracle :) these dealers are. Ask that dealer what the difference between centrifugal and centripetal is, I d love to hear that one.