Notices
991 GT3 GT3RS and 911R
Sponsored by:

.Higher Octane Fuel

 
Old 08-09-2014, 09:38 AM
  #1  
CALSE
User
Thread Starter
 
CALSE's Avatar
 
Join Date: Aug 2014
Location: OC
Posts: 385
Likes: 0
Received 0 Likes on 0 Posts
Default .Higher Octane Fuel

Does anyone know what the highest octane fuel mixture the stock tune will efficiently accommodate?

Last edited by CALSE; 08-11-2014 at 04:15 AM.
CALSE is offline  
Old 08-09-2014, 09:50 AM
  #2  
LexVan
Addict
Rennlist Member
 
LexVan's Avatar
 
Join Date: Jan 2013
Location: Chicagoland Area
Posts: 20,038
Likes: 0
Received 111 Likes on 61 Posts
Default

2 summers ago, I played around and used a ton of 98 octane unleaded. No track duty. The only difference I felt was in my wallet ($8.00/gallon....IIRC). My right foot was telling my left brain the cars felt faster, but someone was BS the other. I think a stock tune maxes out at just over 93 octane.
LexVan is offline  
Old 08-09-2014, 10:09 AM
  #3  
Nick Yoskin
User
 
Nick Yoskin's Avatar
 
Join Date: Nov 2013
Posts: 750
Likes: 0
Received 0 Likes on 0 Posts
Default

oxygenated fuel is what you need. That will make more power.
Nick Yoskin is offline  
Old 08-09-2014, 10:58 AM
  #4  
LexVan
Addict
Rennlist Member
 
LexVan's Avatar
 
Join Date: Jan 2013
Location: Chicagoland Area
Posts: 20,038
Likes: 0
Received 111 Likes on 61 Posts
Default

Originally Posted by Nick Yoskin View Post
oxygenated fuel is what you need. That will make more power.
I think you mean unoxygenated...... meaning without any ethanol. Pretty hards to find in 93 octane. Yes for 91. Some tracks have no ethanol 93 or 98. North of $6/gallon.
LexVan is offline  
Old 08-09-2014, 11:11 AM
  #5  
Haku
Addict
Rennlist Member
 
Haku's Avatar
 
Join Date: Mar 2006
Location: Southeast
Posts: 3,112
Received 2 Likes on 1 Post
Default

No ethanol 93 is def the way to go. Much better in every way.
Hopefully it's available in your state.
http://pure-gas.org
Haku is offline  
Old 08-09-2014, 09:30 PM
  #6  
Mike in CA
Addict
Rennlist Member
 
Mike in CA's Avatar
 
Join Date: Jun 2001
Location: North Bay Area, CA
Posts: 11,865
Likes: 0
Received 1 Like on 1 Post
Default

There's no point in using fuel with higher than 93 octane as Porsche states max performance is achievable with 93. For the street the 91 that is readily available is adequate. For timed events, I buy some expensive 100 octane unleaded and blend a few gallons with my the 91 in the tank to bring the average up to 93+. I don't know how much difference it makes, but I feel better about it.
Mike in CA is offline  
Old 08-10-2014, 01:01 AM
  #7  
Drifting
Addict
Rennlist Member
 
Drifting's Avatar
 
Join Date: Oct 2013
Location: LA
Posts: 3,290
Received 4 Likes on 4 Posts
Default

Originally Posted by Mike in CA View Post
There's no point in using fuel with higher than 93 octane as Porsche states max performance is achievable with 93. For the street the 91 that is readily available is adequate. For timed events, I buy some expensive 100 octane unleaded and blend a few gallons with my the 91 in the tank to bring the average up to 93+. I don't know how much difference it makes, but I feel better about it.
Is a California thing that you guys don't have 93 octane available anywhere in the state? 93 octane is available in most states on the East Coast.

Also I agree with both you and Haku. With you that buying more than 93 octane doesn't accomplish anything. I agree with Haku that the ideal gasoline for our GT3s would be 93 octane without ethanol
Drifting is offline  
Old 08-10-2014, 02:29 AM
  #8  
sk0t
User
 
sk0t's Avatar
 
Join Date: Mar 2014
Location: Adelaide, South Australia
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
Default

My dealer in Adelaide also recommended against ethanol-blended fuels. I plan to run the same Mobil 98 RON fuel (US 93-94) that I've used almost exclusively in my STi and RS4.
sk0t is offline  
Old 08-10-2014, 02:31 AM
  #9  
Mike in CA
Addict
Rennlist Member
 
Mike in CA's Avatar
 
Join Date: Jun 2001
Location: North Bay Area, CA
Posts: 11,865
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Drifting View Post
Is a California thing that you guys don't have 93 octane available anywhere in the state? 93 octane is available in most states on the East Coast.

Also I agree with both you and Haku. With you that buying more than 93 octane doesn't accomplish anything. I agree with Haku that the ideal gasoline for our GT3s would be 93 octane without ethanol
You East Coast guys are lucky with regard to the 93 octane. California is generally only 91 octane. Nevada and Arizona and the Rocky Mountain States too, I think but maybe RL'ers from those areas can confirm.
Mike in CA is offline  
Old 08-10-2014, 03:35 AM
  #10  
hzoenvy33
User
 
Join Date: Mar 2014
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default

I always wondered how the GT3 engine is able to make 475hp in the US with 93 octane and in Europe you have to put in 98 octane to get 475hp while 95 octane means "reducing" peak power....
hzoenvy33 is offline  
Old 08-10-2014, 07:14 AM
  #11  
sk0t
User
 
sk0t's Avatar
 
Join Date: Mar 2014
Location: Adelaide, South Australia
Posts: 102
Likes: 0
Received 0 Likes on 0 Posts
Default

Because the US octane numbers are the average of RON and MON, which is also known as the AKI (Anti-Knock Index); see http://en.wikipedia.org/wiki/Octane_rating for more details.
sk0t is offline  
Old 08-10-2014, 08:45 AM
  #12  
Bacura
User
 
Bacura's Avatar
 
Join Date: Sep 2013
Posts: 1,710
Likes: 0
Received 0 Likes on 0 Posts
Default

Which is better. 91 with no ethanol or 93 with ethanol? Those are my 2 choices. Shell is the 91 no ethanol and is nitrogen enriched whatever that means.
Bacura is offline  
Old 08-10-2014, 09:12 AM
  #13  
Haku
Addict
Rennlist Member
 
Haku's Avatar
 
Join Date: Mar 2006
Location: Southeast
Posts: 3,112
Received 2 Likes on 1 Post
Default

Originally Posted by Bacura View Post
Which is better. 91 with no ethanol or 93 with ethanol? Those are my 2 choices. Shell is the 91 no ethanol and is nitrogen enriched whatever that means.
I would go with 91 No Ethanol. I have no scientific knowledge to base my preference on, I just don't like ethanol and the damage it does to hoses and engines.
Haku is offline  
Old 08-10-2014, 09:51 AM
  #14  
LexVan
Addict
Rennlist Member
 
LexVan's Avatar
 
Join Date: Jan 2013
Location: Chicagoland Area
Posts: 20,038
Likes: 0
Received 111 Likes on 61 Posts
Default

Originally Posted by Bacura View Post
Which is better. 91 with no ethanol or 93 with ethanol? Those are my 2 choices. Shell is the 91 no ethanol and is nitrogen enriched whatever that means.
I always say octane rules. So. I'd take the 93 with ethanol. Most fuels I've tested with my ethanol testing kit shows ethanol levels right around 5%. Max I've seen was 9%. I think they do this to be within a safe range for the legal claims at the pump, "less than 10% ethanol".

A modern Porsche is built for these 10% ethanol levels.

When storing your car for a few months, make sure the tank is very-very full, and stabilize the fuel with a product like Sta-Bil at a minimum of 1 ounce per 2.5 gallons fuel. Double dose for storage exceeding 6 months.
LexVan is offline  
Old 08-10-2014, 09:54 AM
  #15  
Nick Yoskin
User
 
Nick Yoskin's Avatar
 
Join Date: Nov 2013
Posts: 750
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by LexVan View Post
I think you mean unoxygenated...... meaning without any ethanol. Pretty hards to find in 93 octane. Yes for 91. Some tracks have no ethanol 93 or 98. North of $6/gallon.

Nope....e15 and oxyoganted fuels are two completely different things. Google it.
Nick Yoskin is offline  

Thread Tools
Search this Thread
Quick Reply: .Higher Octane Fuel


Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: