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Optimax Extreme (100ron + 5% Ethanol)


Zahos

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Ethanol has a higher oxygen content in it than your normal fuel, which will lean the car out. I have seen examples of cars tuned for 98RON at 11.8:1 AFR's and when filled up with E10 they leaned out pretty badly (this is also evidenced in the HPI GTR special that came out a few weeks ago). Octane rating has nothing to do with it, its simply the fact the fuel has alot more oxygen in it than normal, and for the car to run properly on it, the ECU needs a retune. Wether the stock ECU can compensate for such a rise or not, I have no idea, but I dare say that may be why Nissan reccomend against using it.

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why would a higher RON rated fuel cause problems?

If my car is tuned for 98RON, and I use 92RON, then yes it will.

But if it is tuned for 98RON, and I use 100RON, then the chances of pinging decrease, not increase.

That's not entirely true.

It'll depend on if your ECU has a learning function, and how close to the edge you've tuned it.

Running a high RON fuel in an engine designed for lower run can be just as bad. Because the higher RON fuel burns at higher temps (allowing you to run more advance / boost because of its resistance to detonation), at lower tunes it may not ignite at all. If your engine is pumping in a certain amount of fuel because of the air going into it, and the fuel won't ignite......it runs lean and has bad fuel economy / emissions.

One of my friends had this problem with an early Excel. They tried running it on Optimax (back when it was the only 98RON around) for a while, and noticed that it was audibly pinging and smelled like shit. Tried several different servos, etc, all the same.

Eventually they took it to the Hyundai mechanic, who said the ECU in them was so shit that it couldn't cope with fuel that doesn't ignite easily, and since it was tuned for regular unleaded the results speak for themselves.

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I can't believe this. THis Zahos is telling everyone that they are pulling information fom their asses.. when he is just reading shit, taking it as fact and telling everyone else they are wrong?

Its all crap. Zahos, you obviously have very little knowledge on cars, motors and their related physics. Maybe you should sell your Skyline and buy a Starlet or something.

Anyway, talking to my tuner, who is very reputable, tuned my car to perfection, and everyone elses around said a few things about the 91 blend etc.

He said that if he could, he'd run STRAIGHT ethanol in his ute, car etc, he would, and the only reason some performance cars run like crap is beacuse they aren't tuned for it.

Simple. Ethanol doesn't kill cars, tunes do.

So Zahos, pull your head out of your ass, stop believing all this shit that you read on all these websites, and learn the facts. Learn what it actually does.

nissan and all of those other companies are too lazy to carry out tests, or already have and have relised that their tunes won't work so instead of saying that the tunes don't work, they just say

"OMFG, ETHANOL!!11 IT'S A BAD MOFO LIKE YOUR MUM! OMFG TELL THE WOMEN AND THE KIDS!!!!11111oneoneone11!1111!!!111"

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thats all well and good but the point is.

i haev a fully tunable ecu

am i going to make more power with 98ron optimax or 100ron e10 optimax extreme.

when retuned as far as i know the e10 fuel will be lese dense so i cant run it as hard, so i would lose power?

is this a correct assumption?

this is how i view it.

mick

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It doesn't damage your actual motor.

There's roumers its simply harder on your fuel system.

Running toluene would be worse.

But.. I have no idea. :P

umm it has toluene in it as well.

and its the fact that E blended fuel have a tendancy to wear out fuel componts and seals and the like.

Ethanol has been around for many years as has toluene.

there is nothing wrong with it for cars that can work with it, where nissan has said not too use it then i wont use it.

as for more power well who knows, i have used all the 98RON fuels and i find that vortex is the best then BP then shell is the worst this is for my car that dont mean that its gospel and is the same for all cars.it coulda been that when i used the shell stuff that it was a bit older and therefor the octane rating had dropped from 98.

if you use a 98ron fuel in a car tuned for 91-95 then it will make not much difference at all it can actually be detremental for the car and loose power and instead of cleaning it it could actually carbon it up.

but using 91-95RON fuel on a car designed for 98RON that is worse, my gf new car Golf GTi needs 98 to run cannot use anything less then that, and VW say that you can use ethanol in there cars without a problem so i will be waiting for it too come closer too me out penrith way and then tell her to try a few tanks of it and see how it goes, but i wont be putting it in my pulsar that is for sure.

goto this link to find out about the cars compatability with ethonal fuels

http://www.fcai.com.au/ethanol.php/2004/11/00000001.html

and here for the safty and spec sheet on the new fuel

http://www-static.shell.com/static/au-en/d...ds_version1.pdf

SSS_Hoon

Edited by SSS_Hoon
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Ethanol has a higher oxygen content in it than your normal fuel, which will lean the car out. I have seen examples of cars tuned for 98RON at 11.8:1 AFR's and when filled up with E10 they leaned out pretty badly (this is also evidenced in the HPI GTR special that came out a few weeks ago). Octane rating has nothing to do with it, its simply the fact the fuel has alot more oxygen in it than normal, and for the car to run properly on it, the ECU needs a retune. Wether the stock ECU can compensate for such a rise or not, I have no idea, but I dare say that may be why Nissan reccomend against using it.

I think your missing the point an AFR probe measures the oxygen content of the exhaust fumes so a fuel with a high content of 02 displays a richer mixture. This is why when you run NOS onto of a normal tune it runs richer as the NOS carries its own oxygen. The reason that it is leaning out is because of the desity of the fuel is less than normal 98 RON unleaded it was tuned for. Ethanol is essentially a solvent so it will decarbonise your motor which may in turn lead to clog injectors or the like I think this is the risk you take.

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E10 is great stuff... theres potential for a solid power gain over reeglar optimax.

You need to retune your motor though. If you expect to be able to just chuck it in and "she'll be right mate" then you are an idiot and deserve a car that runs like complete shit.

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My 2 cents worth...... I've tried that "Boost 98" from United which is also E10. Guess what, my stock as a rock GTR32 ran like shit on it. It missed, farted, backfired, wouldn't accelerate etc etc etc .....

I wouldn't recommend E10 fuels either.

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There is a service station near my place that sells the stuff, ill put a 1/2 tank in next week and see how things go.

Definatly this is for everyone to work out.

My car has the standard computer with a std tune, so ill see what happends.

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My old RB20DET with std ecu running 1bar used to run fairly lean (13:1) through the mid range then go rich at the top end.

I suspect with such mods my little rb20det wouldn't have suited the e10 stuff.

Edited by Cubes
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I think the point of increasing the RON was because of the fact the fuel is less dense. So while it may run a little leaner in theory it shouldn't succumb to spontaneous combustion as the extra toluene is there to compensate.

You have got to remeber that ethanol has a lower heat of vaporization which may be the cause of less fuel in the combustion chamber; hence a leaner condition but its spin off is in cooling the charge.

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Pfft Nissan told us not to run unleaded back in 1980 as well....they just dont want to certify the cars for it incase anything does come up as warranty.

I'll guarantee there is no difference in the fule system of a 2004 nissan v a 2005 nissan that makes it magically OK.

And....if ethanol does have more oxygen than regular fuel, what is the problem there? can anyone answer why N20 (NOS to the ricers) gives more power to an engine? You just need the tune if it is a significantly different o2 content.

Remembering that a normal fuel mix has 12 times as much oxygen as petrol it would have to be a big difference in the fule to change the ratio significantly.

cc, it is the fuel companies that have been using their contacts for years to keep competition from ethanol away....I bet the combined fuel companies have more political clout than some cane farmers

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