Fuels ain't Fuels

Johnik · Post by **Johnik** » Sat Feb 25, 2006 10:45 am

Hey people,

Found this article in the recent Royal Auto. Thought it may be of some interest to everyone. Definatly worth the read if you've ever stood at the bowser and thought "why is this shit 10c more than that shit and whats the diff

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photomike666 · Post by **photomike666** » Sat Feb 25, 2006 1:12 pm

Interesting to see the 0-100 was faster on both test cars using 95RON than it was with 98RON. I have to say I can feel the difference between the octanes on the bike. It feels smoother using 98, accelerates harder and revs out more easily. Fuel economy is very similar.

However, I find having the exhaust baffle in or out makes far more difference. With the baffle in the economy is better, there is more mid range power and the bottom end feels smoother. Take the baffle out and the power delivery at the bottom end is harsh, mid range looses a bit and the top end gains loads. Fuel economy goes down, partly due to the freer revving engine, but also because the added power gets used more

Oh, and it sounds stifled with the baffle in (apparently my bike is a bit loud without the removable baffle, damn I love Staintune).

Neka79 · Post by **Neka79** » Sat Feb 25, 2006 2:08 pm

photomike666 wrote:Interesting to see the 0-100 was faster on both test cars using 95RON than it was with 98RON. I have to say I can feel the difference between the octanes on the bike. It feels smoother using 98, accelerates harder and revs out more easily. Fuel economy is very similar.

However, I find having the exhaust baffle in or out makes far more difference. With the baffle in the economy is better, there is more mid range power and the bottom end feels smoother. Take the baffle out and the power delivery at the bottom end is harsh, mid range looses a bit and the top end gains loads. Fuel economy goes down, partly due to the freer revving engine, but also because the added power gets used more Oh, and it sounds stifled with the baffle in (apparently my bike is a bit loud without the removable baffle, damn I love Staintune).

yea i saw it on tv the other nite....altho remeber, sum bikes/cars are designed to run on PULP, and may cause pinging/probs if not run on 98...

they also spoke to a few mech's who recommended PULP, but the evidence didnt back it up...and remeber the 95 or woteva it was falcon doesnt have the compression of a 05 zx10r....they mentioned in the article that u should run it on 98ron if specified by manufacturer, and if its a japanese vehicle..

Johnik · Post by **Johnik** » Sat Feb 25, 2006 2:22 pm

Yeah, if the manufacture specs 98 then by all means run 98. I guess what the point is that if you have an older bike not setup for using higher octane fuels stick to the base unleaded and save yourself the cash. I know what I'll be running...

Johnik · Post by **Johnik** » Sat Feb 25, 2006 2:22 pm

Yeah, if the manufacturer specs 98 then by all means run 98. I guess what the point is that if you have an older bike not setup for using higher octane fuels stick to the base unleaded and save yourself the cash. I know what I'll be running...

Gosling1 · Post by **Gosling1** » Sat Feb 25, 2006 3:21 pm

gawd we've done this topic to death a few times now..........

its always good to see it raised again

Our old VN Dunneydore runs *heaps* better on plain-jane 91 unleaded than anything else. (Aussie-built, and designed for normal unleaded)

The Prado runs like shit on 91, and runs *great* on 95 or 98. (Imported, and as per the recommendations of the manufacturer) - Any Euro import should also use 95 or 98.

The Z1000 runs *great* on 98, but only because it has high-comp pistons fitted......the other Zeds all run on 91 only, its fine for them.

Cannot run the ZX12 on anything under 95 octane..........

95 or 98 octane is a WOFTAM unless your engine is designed for it. Full stop.

jpbikeboy · Post by **jpbikeboy** » Sat Feb 25, 2006 3:46 pm

the reason for a drop in performance with the 98 is because you actually lose power with any unused octane.eg if your motor only needs 95 to stop detonation then the extra that 98 has in it will decrease performance.

gizmo · Post by **gizmo** » Sat Feb 25, 2006 4:59 pm

What about that with the higher density 98 octane your engine will run richer & therefore lose power?

I don't think any factory fitted ecu has closed loop fuel control unless your on a constant throttle like cruising.

Most can control ignition timing via a knock sensor, but even that gets turned off over a certain rpm as the mechanical noises will interfere with its reading.

Tune the engine for it & then you maybe away! That's the point with anything that has performance.

Dyno · Post by **Dyno** » Sun Feb 26, 2006 12:04 am

just put my 2c worth in. i work @ mercedes benz as a motor mechainc and we often get car's in running rough, missing or even stalling at light. the main prob is the fuel, drain the shit norm ulp and put in $20 on 95 preium and they run beautiful. i run all my stuff with preium even my lawn mower. ulp doesn't even smell like fuel anymore.

Felix · Post by **Felix** » Sun Feb 26, 2006 12:37 am

Deja vu...

I ended up running my old BMW on 98RON fuels - because that is what it was designed for. No pinging!

I drive out of BP servo's that only have ULP and Ultimate when I go to fill our current cars. I have been saying for a couple of years, and I think I posted it in here once before, that I have found no discernable difference between PULP and the 98's in either of these cars, besides the fact that the 98 stuff is dearer.

I am not sure that Vortex is actually a 98 - I thought it was a 95-96?? <edit: there is a Vortex 98 - name says it all> I know it isn't as dear as Ultimate, Optimax, etc...but our Clio seems to run better on Vortex than anything, though I don't have any empirical evidence to support this - though I average 5.6L/100km - I think the XJ uses somewhat more than that

I don't understand people that try to save money putting lower grade ULP fuel in cars designed for PULP - all it does is increase consumption and make it run like junk negating any savings. But then, I remember rule #1: People are idiots, and it all makes sense again...

Isn't it funny? You'd have thought with leaded petrols demise fuel choice would have been limited to two types...no! Now we have ULP, Ethanol blend ULP, PULP, Ethanol PULP, 98 PULP, some new Ethanal blend 100 RON...

It is marketting and gimmickry at its finest, folks.

PS

I can certainly say that driving style plays a very large factor in fuel consumption. Patient and steady saves roughly 20-30% over impatient people that need to swap lanes every 3 seconds to make roughly 2 seconds total gain on their trip of 30km...if you are in fairly heavy traffic, just relax, face the fact that it will take a bit longer this time, and just keep the pace steady. You'll save heaps without spending any extra on gimmicky fuels...

javaman · Post by **javaman** » Sun Feb 26, 2006 12:41 am

Gosling1 wrote:
95 or 98 octane is a WOFTAM unless your engine is designed for it. Full stop.

I agree. Higher octane fuel actually is designed to burn slower to avoid pinging! Advantage is gained from higher compression.

The J1 is specified to use premium, but putting regular is ok an in fact more power! So long as I don't push it too hard it pings. How convenient there is only a regular servo before reefton wink:

mrmina · Post by **mrmina** » Sun Feb 26, 2006 10:04 am

i also find that diiferent fuels work differently.

the 98 mobil fuel is the one i try to use as much as possible, but i heard regular unleaded works well on my model bike too.

gizmo · Post by **gizmo** » Sun Feb 26, 2006 4:13 pm

& I don't think the ethanol mixed fuels are real good either.

Johnnie5 · Post by **Johnnie5** » Sun Feb 26, 2006 4:20 pm

its a case of try them all for a few tanks each and use what works best

FWIW on the wok rodeo i used

91 and got 400K to a tank
95 get 420 a tank
98 get 380 a tank

so the 95 gets the nod and works out the same as using 91 and the extra 20 kays or so is worth not having to fill up all the time

but as already said and found it some vehicles get an improvement , some get worse , its all a case of suck it and see

Post by **Wattie** » Sun Feb 26, 2006 4:22 pm

Cars tested were falcoon and fiesta,
it was on "a current affair" in syd, and it stated these results would only relate to cars designed to run on normal unleaded petrol.
i've had my car on the dyno twice and about 3 kws difference when running 98 octane compared to 95. (give or take temp and stuff)
my car states "PREMIUM UNLEADED ONLY" so i guess its designed to have the good stuff...
not liek the good ol' falcoons