Kawasaki Sportsbike Riders Club - Australia - Online Forum

hi all , my ride is zx2r A version, and i have been using ultimate for the last couple of tanks and found it had no difference than any 95 octane unleaded fuel,

however the question is does it really clean the engines like the way it should do to cars?

or....................?

I watched an episode of Fifth Gear (or maybe it was Top Gear), where they tested Ultimate, Optimax and standard ULP in various cars on a dyno.

They found that if the car was designed to run on the high octane fuels then the car produced more horsepower.

the larger bikes are built to run on high octane fuels, I would doubt you would notice it on the 2 fiddy. But hey i could be wrong !!

Just use whatever octane number or RON is in your user manual.

If you use a higher octane fuel than the engine is designed for, you're not going to get any more power despite paying more per litre for the fuel, and in some cases you'll actually soot up your spark plugs because of the slower flame front of higher octane fuels. Higher octane does not mean higher power unless the engine it's running in is designed to take advantage of the combustion characteristics of higher octane fuel.

If you use a lower octane fuel than the engine is designed for, you'll potentially end up with the engine pinging. The reason a lot of modern fuel injected engines (eg European car engines) will develop more power with higher octane fuel is because they're designed for higher octane fuel, but can also detect lower octane fuel and adjust the ignition accordingly to prevent knocking (although power is reduced in doing so).

Of course BP Ultimate might be a better choice than standard octane ULP from a dodgy operator who adds ethanol, paint thinner, and any number of other things to it. But providing the fuel is of equivalent quality, there is no performance advantage in running any other fuel than the one the engine was designed for in the first place.

At least that's what I've been told.

IMO don't waste your cash on 95 octane.. go either 91 or 98.

I've heard that 95 is very up and down.


With fuel prices atm, I tend to just use 91 personally and if I'm going for a spurt in the twisties through a tank of 98 in to give it a good run.


Dan

I use that shell 95, i was told to stay away from optimax as it has to much additivies in it it mucks up you engine

blue12 wrote:the larger bikes are built to run on high octane fuels, I would doubt you would notice it on the 2 fiddy. But hey i could be wrong !!

Well, the ZXR250 runs, from memory, 12.4:1 compression, which is, for a production motor designed in the late 80's, prety faken high; high enough to appreciate high-octane fuel, in any event.

I ran mine on the Optimax for a while back at the turn of the century. Didn't have any adverse effects...

I put optimax in the ZZR1100, that's the way to go isn't it??? I run it in my old holden V8 too as I know it runs good there, stops the *pinging*

Standard ULP on a ZXR250 should be good enough. In regads to OPTIMAX I would not recommend this for this bike as you will find that your sparkies would muck up a lot quicker. Also you will find that starting in the morning is a lot harder simply because of the ignition point of the optimax is about 98 or so degrees higher than standard ULP. With the ULTIMATE I have not actually seen the specs so I can't give a definite answer on that. I suggest that try running only standard fuel for a while and see how it goes. You never know you might save a bit of money.

Jeff

http://www.ksrc-au.com/phpBB2/viewtopic ... t=opticrap
This previous post will just about cover all s
some very good reading IMHO

yes, that thread Sulli has listed does cover a lot of the issues.
Basically, at 4 or 5 cents a litre difference, you can expect to pocket about $1 saving using the cheaper fuel..........imho, its hardly worth it. Your 250 may not be noticeable different with higher-octane fuel, but it sure makes a difference in a larger-capacity bike, especially the sports bikes with high-comp motors.

Craptimax is the fuel that *cleans* your motor, not BP Ultimate. Use it at your peril. Its crap.

My ZZR gets about 20-30km more out of a tank of regular than one of premium (95 OR 98) during a commute. If I'm playing, it's much of a muchness, although the premiums tend to kill the spark plugs. The only non-standard items on the bike are the rack, tyres and brake pads. In the past it has pinged badly on 91 octane fuel, from different fuel outlets. Now I reckon it was merely a batch of bad fuel, because it certainly doesn't ping now. It has a compression ratio of 11.5:1, which is not in the league of the 250, but not exactly low.

Verdict - total waste of time and money to put in anything other than 91. It starts easier, runs smoother and has better throttle response simply because it runs cleaner without fouling plugs.

My '84 VF500F has a compression ratio of 11.1. It wants premium. It pings on 91, runs moderately well on 95 and loves 98. Modified parts - cams and carb jetting.

My point? Much the same as others - premium petrol is useful if the vehicle is designed or tuned to take advantage of the higher octane. And Optimax is no better or worse than other 98 octane fuels.

How much HP has a ZX2R got?
i'm guessing thats why you dont notice a differance
but will help stop pre ignition (pinging) in higher comp engines
the 98 Octane rated fuels also have cleaners in the fuel

i wont run mine on anything else other than BP Ultimate
and i always get a receipt
you have to remember BP has a fuel Guarantee

What Lucas said he's a clever bloke with a "Crim" & he keeps records ... thats good enough for this ol boy.
Petrols cheap ...... AVGAS is expensive.
Cheers Brett

I have heard these horror stories in the past about using SHell Optimax in modern Fuel Injected bikes. But I always ran the 636 on Optimax, without a hitch. However the Honda guys said strictly no Shell optimax in the new Honda, as it is too dense for the injectors aparently and any small particle will block the injectors. Have been reccommended to use BP Ultimate!