View Poll Results: What kind of fuel for your baby?
Regular unleaded (87)
23
21.30%
Mid-grade unleaded (89)
9
8.33%
High-grade (premium) unleaded (91, 92, or 93 - whatever your area has)
71
65.74%
50/50 unleaded & race gas
0
0%
Pure race gas baby! It ain't that much more expensive than pump gas anyway!
4
3.70%
Methanol! I NEED to run 50 psi of boost!!!
0
0%
Other (explain)
1
0.93%
Voters: 108. You may not vote on this poll
What kind of fuel do you guys run?
09-26-2005, 04:00 PM
#31
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Nope, we use a different equation for calculating octane...it's called the Anti Knock Index, or AKI method.
Good information on all of the octane calculations here: Wikipedia
Good information on all of the octane calculations here: Wikipedia
09-26-2005, 10:29 PM
#33
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I use 93. Amaco/BP Ulitimate only. It give me the best mileage and the smoothest running. If I'm stuck I look for a Mobile or a Shell. Shell gas just doesn't seem to have any oomph to it... Its only a $1 or so per fill up, so I don't feel its a waste. My GTO and Maxima both require 'Premium'
09-26-2005, 10:41 PM
#36
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Yeah... it doesn't seem to run properly on BP 91 octane... gets crappy mileage too... the ONLY fuels I'll put in it are Shell or Conoco 91 octane.
09-27-2005, 06:45 AM
#37
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Originally Posted by Ken D
Octane ratings (aka "antiknock index") in the US are calculated using the RON+MON/2 method. US octane ratings are about 4-5 points below EU RON. So your 95 is about the equivalent of 91 US, 97/98 RON runs about 93/94 US.
Never needed anything else than the 98RON ..built right,most engines can take 30 psi boost with that fuel. Unless they break mechanically,that is... and race fuel here is $23 per gallon...
09-27-2005, 09:02 AM
#38
Nordschleife Master
This poll would be valuable if the choices included what the octane spec is and what the octane used is. Also, octane spec goes up with chips, but I suspect that's more CYA or marketing for the chip guys as they don't change the CR and a richer mixture is _less_ likely to knock.
Nonetheless, apparently many people use higher octane than needed.
Dudes, that's 10 or 20 cents per gallon out the tailpipe. If you heard knocking, that's one thing. Just putting it in for no reason is, well, stupid.
Nonetheless, apparently many people use higher octane than needed.
Dudes, that's 10 or 20 cents per gallon out the tailpipe. If you heard knocking, that's one thing. Just putting it in for no reason is, well, stupid.
09-27-2005, 09:52 AM
#39
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Originally Posted by GlenL
marketing for the chip guys as they don't change the CR and a richer mixture is _less_ likely to knock.
09-27-2005, 10:32 AM
#40
Rennlist Member
I run 91, 92, or 93 (whatever's in the premium pump). But I have to admit that I've been toying with the idea of mixing in a few gallons of tolulene for a DE just to see what it would do. Anybody try this before? What were the results?
09-27-2005, 11:52 AM
#42
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I run my turbo at 21psi boost. It runs best on a mix of 3 gallons of toluene to a tank of 91 premium. I also use 100 octane race fuel from Union 76, but the car runs stronger on the toluene mix.
09-27-2005, 12:12 PM
#43
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I run 87 octane in the 951. Never had any knock or detonation problems in it, even at about 13psi of boost (then again, when it ran badly, I didn't get knock at 23psi with 87 octane either...).
By using the low grade fuel you are loosing performance with your turbo guaranteed.
You may not hear knock because your knock sensor hears it first. Then it retards your timing and or adds fuel. This is the wonder that is computer controlled engine management.
So you think you all is well with the low grade fuel, but the engine management is hard at work dealing with it. The Bosch brain will basicly turn your engine into a low performance engine to deal with the poor fuel. Porsche does not make recomendations, like fuel grades, lightly.
To prove the point, fill up your turbo with two tanks of high grade fuel. If not on the first tank, by the second tank, I'll bet you will see a difference. Especially if you run 100 octane with 23 psi of boost!
09-27-2005, 12:19 PM
#44
Rennlist Member
Originally Posted by Bill
I run my turbo at 21psi boost. It runs best on a mix of 3 gallons of toluene to a tank of 91 premium. I also use 100 octane race fuel from Union 76, but the car runs stronger on the toluene mix.
