Registered: Mar 2006
Location: between boston and NYC
hey im on vwvortex too, i have like 4000+ posts on there. if you can afford it, get the best gas available to you - i always run 93 in my 2002 vr6. i would run at least 91 in your 1.8T if you cant afford 93.
Apr-22-2007 16:31
EarnYourKeep
LIT
Registered: Dec 2001
Location: twentyonetwo
quote:
Originally posted by gehzumteufel
normally id say 91, but since i have no clue on your driving style i cant say either is better. do you stomp on the gas? if so use 91. if you just put put around then 87 is fine since you wont be doing any heavy acceleration.
kid nyce: the octane rating has nothing to do with a/f ratios. its all for detonation aka knock.
octane rating does play a part in AF ratio, if you have forced air induction like the part a turbo plays. increased hp/t.lb is determined by amount of cool air and fuel. if you're fuel is running 'RICH' alot of gas that burns quicker (higher octane) same goes for if you're fuel is running 'LEAN', meaning more air and less fuel or burns not as clean (lower octane).
knock/internal det usually identified by a CEL has nothing to do with octane ratings, it has to do with driving style. If you SLAM the gas you potentially feed too much gas into the engine thus creating a 'mini explosion' inside the engine. usually happens on automatic vehicles where drivers bring the RPMs up high enough before the redline, ease off the gas, then slam it passed the next set of gears. thus filling the engine with gas to raise the RPM, the over-acceleration at this point burns all the gas you filled in getting up the RPMs and causes a mini-explosion in the engine.
driving style and internal det/knock has nothing to do with the octane you're burning but more on the caution of how much air to fuel you are pushing especially with forced air induction.
I'm probably wrong but thats how i learned it...then again i haven't owned a car in probably like 4 years so i take the train now lol
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I PUT TRADEMARKS AROUND YO MOTHAFUCKIN EYE
JUST ME N YOU
Apr-22-2007 17:54
tiesto14
Let The Music Play
Registered: Oct 2001
Location: The Palladium New York City
frig 87,91 and 93 use Cam 3
___________________
Bring back 1994 NYC clubbing nights, cus the sh*t today is filled with junk parties and DJs that play sh*t House.....Zabiela, Sander, or Howells and all the rest suck and couldnt throw a night like it was in the early 90s in NYC!!!...Screw Twilo - give me Limelight circa 1993!!!
Apr-22-2007 19:17
EXTREMUM
Senior tranceaddict
Registered: Aug 2006
Location: New York, USA
Re: Re: Re: question for the car buffs
quote:
Originally posted by lücid
for those of you who are saying "NEVER" use 87 on a turbo, can you explain to me why you say that?
87 octane isn't stable enough to take on turbocharged engines. It can easily pre-ignite within the combustion chambers, and fry the everything inside the cylinder head. Visually, the results would be comparable to the consequences of a blown head gasket. Then, you can spend thousands on getting the motor rebuilt.
Apr-23-2007 03:50
gehzumteufel
In your ass
Registered: Nov 2005
Location: so cal
quote:
Originally posted by kid nyce
octane rating does play a part in AF ratio, if you have forced air induction like the part a turbo plays. increased hp/t.lb is determined by amount of cool air and fuel. if you're fuel is running 'RICH' alot of gas that burns quicker (higher octane) same goes for if you're fuel is running 'LEAN', meaning more air and less fuel or burns not as clean (lower octane).
knock/internal det usually identified by a CEL has nothing to do with octane ratings, it has to do with driving style. If you SLAM the gas you potentially feed too much gas into the engine thus creating a 'mini explosion' inside the engine. usually happens on automatic vehicles where drivers bring the RPMs up high enough before the redline, ease off the gas, then slam it passed the next set of gears. thus filling the engine with gas to raise the RPM, the over-acceleration at this point burns all the gas you filled in getting up the RPMs and causes a mini-explosion in the engine.
driving style and internal det/knock has nothing to do with the octane you're burning but more on the caution of how much air to fuel you are pushing especially with forced air induction.
I'm probably wrong but thats how i learned it...then again i haven't owned a car in probably like 4 years so i take the train now lol
heres what i have been told by a bunch of people cause i at one time thought the same thing. RICH causes elevated n2o levels which causes the burn to be not as clean and causes higher heat and lost power. i could be wrong though too. we both could be partially right. i have no clue. i need to do the research again so that i understand this stuff fully. i just have never really taken the time. not something i personally am too concerned with as i dont have a crazy modified car.
Apr-23-2007 14:42
hiram
vrooom!
Registered: May 2005
Location: Miami, United States
Re: Re: Re: Re: question for the car buffs
quote:
Originally posted by EXTREMUM
87 octane isn't stable enough to take on turbocharged engines. It can easily pre-ignite within the combustion chambers, and fry the everything inside the cylinder head. Visually, the results would be comparable to the consequences of a blown head gasket. Then, you can spend thousands on getting the motor rebuilt.
+1000
you def need to run high octane gas on forced induction engines. the higher the octane the less chance of pre-ignition. in essence 87 burns with less air needed than 93. listen to what this guy said. you dont wanna go spending thousands of dollars by saving 2 dollars every time you pump
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Apr-23-2007 16:21
The Doros
tranceaddict in training
Registered: Apr 2007
Location: Toronto
First I'd just like to say hi to everyone. I've been browsing these forums for some time now and finally grew the balls to join. So be gentle you c0r whores, ok here goes.
Check your user manual and run whatever it tells you to run. Do not run 93 like some of these people are telling you to. An 87 or 91 will run stable enough and it will not pre-ignite. If that's what VW engineers are telling you to run then run it.
quote:
Originally posted by gehzumteufel
heres what i have been told by a bunch of people cause i at one time thought the same thing. RICH causes elevated n2o levels which causes the burn to be not as clean and causes higher heat and lost power. i could be wrong though too. we both could be partially right. i have no clue. i need to do the research again so that i understand this stuff fully. i just have never really taken the time. not something i personally am too concerned with as i dont have a crazy modified car.
Running Rich will cause high extremly high combustion temperatures which in turn will cause high levels of NOX. So you are correct gehzumteufel just the you got it backwards. Also if you run rich for a prolonged period of time you burn out the cat and bam there goes a couple of hundred dollars.
Apr-23-2007 16:48
lücid
electric girl
Registered: Aug 2003
Location: NY
thanks for all the replies, guys.
i don't think we even have 93 around here, so that's not really an option. there might be a few gas stations that carry it, but the ones i go to usually only carry 87/89/91.