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High octane fuel and the truth

alex2_s

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Quote regarding VS V6 engine management system,

"to achieve optimum engine efficiency, the ECU continually advances the ignition timing until detonation occurs. When detonation occurs, the ECU receieves a low voltage signal which is generated by one or both knock sensors and the ignition timing is instantly retarded".

Would this not mean that the point in which detonation occurs would be later with 98 RON compared to 91 RON, alllowing more advance automatically?
 

ephect

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Who said anything about more fuel?
Dude, do you even know what an octane rating is?

Heaps of people are talking about a 'tune', whatever that is. If you are talking about eeprom/ECU programming, then you should know that you can't change the compression ratio of the engine this way.

Remember, a higher compression ratio is the only reason that you would ever need to change from regular fuel to premium...no other reason. A tune will change how much fuel is injected, when it's injected and a host of other changes to increase performance, but it won't need premium fuel to do it. The power increase comes from the fuel and ignition mapping changes, not the fuel octane rating.

I should have expected the sheep on this forum to trash my thread just because they don't like what I'm talking about. That's fine, but tell me why so we can all learn instead of just calling bullshit. Go and do some reading on what a knock sensor does, and why it does it.

i hardly think discussing is trashing your thread. all that most have asked is to show your workings and references. i can see your points but your points almost assume we all run carby engines with no technology in them.. remember the VS and up can advance timing not much but enough to benefit.
you can take the the same model car, one will love premium the other no difference. there are soo many things your not taking into account, how the engine has been treated if the car is in bad need of maintenence..

i dont need to run 95 or 98 but i like to think im treating my engine.

ok i did said more fuel which isnt the correct word, but im sure you would have understood if you werent so focused on blindly hammering your point across.

i qouted the below because you havent mentioned anything about them which all bring a valid augument to the table.

Your entire perspective seems to to be focused in regards to pre-detonation or pinging.
The big picture includes performance, emissions and residual deposits.
Your claims are accurate only in regards to preventing pre-detonation.
Dyno would show the truth.
I am happy to pay 7% extra for a 3-4% performance gain.

It not only high compression engines that require it. Force inducted engines (which usually have a lower compression ratio than naturally aspirated engines) also requires higher octane fuel to resist pre-ignition of the hot/compressed intake charge. Also I believe there is *some* performance benefits to be had as premium/higher octane fuels burn much cleaner/more efficiently = more torque, and the engine can be tuned to run more timing advance which also produces more torque and better fuel economy. My 2c

Quote regarding VS V6 engine management system,

"to achieve optimum engine efficiency, the ECU continually advances the ignition timing until detonation occurs. When detonation occurs, the ECU receieves a low voltage signal which is generated by one or both knock sensors and the ignition timing is instantly retarded".

Would this not mean that the point in which detonation occurs would be later with 98 RON compared to 91 RON, alllowing more advance automatically?
..

People are missing the point.
On a stock car with a factory tune, and no knock sensor, using premium won't make any difference.

this is true but the op didnt specify any details apart from you'll just waste your money, its all the same.. etc
even a car roughly 15years old, straight from the factory, tune and knock sensors standard, can adjust to premium. obviously you wont see the full benefits compared to a worked donk but it will still be there.

personnally i've run 95 and noticed little results economy wise, but yet run E10 (95) and i get another 100+ kms from a tank.. same conditions both times, depends on too many factors, and at the end of the day, your engines preference :)
 

fabz

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I can only go off personal experience which is by no means scientific. But when I run 98 I get 600 km's to a tank on anything else it's 400 km's. Although I suspect my car is tuned for 98 already as it refuses to run properly on anything else.

lol your telling me you get 200 extra kms because you switch fuel. I really dont think thats correct and i think you should check your data.
 

wraith

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lol your telling me you get 200 extra kms because you switch fuel. I really dont think thats correct and i think you should check your data.

Yeah I know it's weird. I have no clue what is going on. Come up to Mackay, pay for the fuel and I will gladly show you. I got from Mackay to Emerald on one tank with 98. Didn't make it half way on one tank with 95. I don't know I am no expert. As said before I have witness who will back up my claim.
 

Super_Low 91

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Yeah I know it's weird. I have no clue what is going on. Come up to Mackay, pay for the fuel and I will gladly show you. I got from Mackay to Emerald on one tank with 98. Didn't make it half way on one tank with 95. I don't know I am no expert. As said before I have witness who will back up my claim.

i will gladly verify the km's wraith used to drive my ass around all the time
 

Calaber

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Okay, here's a question for you guys who maintain that using premium leads to a 3 or 4% improvement. Obviously, I'm only addressing those with standard V6's, not S/C ones or V8's.

How does that translate in terms of driveability?

Can you "feel" the difference in the way the engine runs? Are you able to detect improved performance ie accelleration?

Wraith claims 50% improvement in fuel economy. I can't believe that, but what about the rest of you - has your economy improved?

Do you continue to use premium because you believe it's better for your car or because you believe it is economical to do so?
 

bloodyricho

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hey cop cars never had a chip i dunno where people got that from they probly feel quicker because they have an lsd they came out with fe2 and lsd thats it

look it up they are a BMZB eprom in the cop V6 and some other in the V8's so "Mr I know everything type" check chips on memcals.com (go dr bob) and ask Green foam or Bob the damn memcals can be tuned for premium with real results and i am running one tune for E10 and one for Premium and can switch between the tunes on the fly. I get same economy out of both fuels but a shitload more power outa the premium on its tune.
 
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minux

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Hmm, i guess I am only imagining the 91 pinging its head off and not wanting to rev over 4k rpm without playing up. Damn that no difference premium.
 

Nanos

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guess my engine tuner is wrong when he said its tuned for premium.

so the rules of higher octane and tuning is all wrong. i think the OP needs to walk into a good tuners workshop and tell them this.

Think they will show you hundreds of dyno charts to prove otherwise.

Also the LS1's have from factory in the standard tune low octane and high octane fuel maps. Therefore i beleive high octane fuel makes a difference.

plus i never beleive whats written in book.
 
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