Notices
991 GT3 GT3RS and 911R
Sponsored by:

any advantage to running non-ethenol gasoline?

 
Old 12-12-2013, 05:43 PM
  #1  
Bluehinder
User
Thread Starter
 
Join Date: Dec 2001
Location: Colorado
Posts: 984
Default any advantage to running non-ethenol gasoline?

They just started selling here for "off road use". $4.20 a gallon. Premium, unleaded.

Any advantage or disadvantage to running it in current 911's? I'm thinking of using it in my GT3 to arrive in January, or my 991 911.

Thanks.
Bluehinder is offline  
Old 12-12-2013, 05:55 PM
  #2  
991 3Turbo
User
 
991 3Turbo's Avatar
 
Join Date: Mar 2012
Location: West Des Moines, Iowa
Posts: 363
Default

I would skip it. Something is awry with your explanation. Is this at a service station or what? If it is a service station they are not gonna let you pull up and fill it up if its off road. Are you sure its unleaded?

I am not from Colorado, but some states(like Minnesota I believe but not Iowa) have ethanol mandates for ALL road gas, this may be the case. Make sure its unleaded. In Iowa here I always run non-ethanol gas in everything I own. Ethanol is very hard on lines and seals, etc.
991 3Turbo is offline  
Old 12-12-2013, 05:57 PM
  #3  
Mike in CA
Addict
Rennlist Member
 
Mike in CA's Avatar
 
Join Date: Jun 2001
Location: North Bay Area, CA
Posts: 11,865
Default

This from Wikipedia:

In theory, all fuel-driven vehicles have a fuel economy (measured as miles per US gallon, or liters per 100 km) that is directly proportional to the fuel's energy content.[55] In reality, there are many other variables that come into play that affect the performance of a particular fuel in a particular engine. Ethanol contains approx. 34% less energy per unit volume than gasoline, and therefore in theory, burning pure ethanol in a vehicle will result in a 34% reduction in miles per US gallon, given the same fuel economy, compared to burning pure gasoline. Since ethanol has a higher octane rating, the engine can be made more efficient by raising its compression ratio. In fact using a variable turbocharger, the compression ratio can be optimized for the fuel being used, making fuel economy almost constant for any blend.[26][27] For E10 (10% ethanol and 90% gasoline), the effect is small (~3%) when compared to conventional gasoline,[56] and even smaller (1ľ2%) when compared to oxygenated and reformulated blends.[57] For E85 (85% ethanol), the effect becomes significant. E85 will produce lower mileage than gasoline, and will require more frequent refueling. Actual performance may vary depending on the vehicle. Based on EPA tests for all 2006 E85 models, the average fuel economy for E85 vehicles resulted 25.56% lower than unleaded gasoline.[58] The EPA-rated mileage of current USA flex-fuel vehicles[59] should be considered when making price comparisons, but E85 is a high performance fuel, with an octane rating of about 94ľ96, and should be compared to premium.
Mike in CA is offline  
Old 12-12-2013, 06:07 PM
  #4  
Bluehinder
User
Thread Starter
 
Join Date: Dec 2001
Location: Colorado
Posts: 984
Default

Originally Posted by 991 3Turbo View Post
I would skip it. Something is awry with your explanation. Is this at a service station or what? If it is a service station they are not gonna let you pull up and fill it up if its off road. Are you sure its unleaded?

I am not from Colorado, but some states(like Minnesota I believe but not Iowa) have ethanol mandates for ALL road gas, this may be the case. Make sure its unleaded. In Iowa here I always run non-ethanol gas in everything I own. Ethanol is very hard on lines and seals, etc.
Didn't think I needed to give a full explanation for an answer. It's an industrial oriented station with contracts with all the heavy industry in town, garbage trucks, plows, etc. Team Petroleum, very reputable. Of course I'm certain it's unleaded. I currently run it in my tractor, snow blower, mower. They just started carrying the premium unleaded. It's very industrial, you show up with a gas can, fill your own can, go to building inside to pay. No body gives a ****. No questions asked. They carry all kinds of gas, including 110 octane racing fuel. It's not a service station.

The guys working there are very cool, beards like ZZ Top, anti govt, they don't pry.
Bluehinder is offline  
Old 12-12-2013, 06:30 PM
  #5  
GrantG
Addict
Rennlist Member

 
GrantG's Avatar
 
Join Date: Jun 2002
Location: Denver
Posts: 9,527
Default

Originally Posted by Bluehinder View Post
Didn't think I needed to give a full explanation for an answer. It's an industrial oriented station with contracts with all the heavy industry in town, garbage trucks, plows, etc. Team Petroleum, very reputable. Of course I'm certain it's unleaded. I currently run it in my tractor, snow blower, mower. They just started carrying the premium unleaded. It's very industrial, you show up with a gas can, fill your own can, go to building inside to pay. No body gives a ****. No questions asked. They carry all kinds of gas, including 110 octane racing fuel. It's not a service station.

The guys working there are very cool, beards like ZZ Top, anti govt, they don't pry.
Hi There - I'm a local and have tons of experience with buying the regular 91 Octane swill (usually 10% Ethanol), pure gasoline (the stuff I buy is from Brad's Conoco in Lakewood), and E85.

A new 911 will definitely run better on Non-Ethanol - you'll be able to feel the difference seat of the pants...

The non-Ethanol stuff will make your car faster than the stuff with up to 10% Ethanol in it. Ethanol has less energy density than gasoline (quite a big difference). You'll also have better fuel mileage with non-Ethanol to offset some of the higher cost.

With my EVO, I can change the fuel map to run on E85 and then I can run the turbo boost to 24psi and get an extra 100hp and ft-lbs than with either gasoline mix. And it only costs $2.75 per gallon for 107 octane.

But unless you have a turbo with adjustable boost and fuel mapping, non-Ethanol stuff is best. The 91 octane stuff with Ethanol is unequivocally the worst.

Which station did you find with non-Ethanol?
GrantG is online now  
Old 12-12-2013, 07:14 PM
  #6  
frayed
Super User
 
frayed's Avatar
 
Join Date: Mar 2004
Posts: 3,972
Default

As a rule ethanol is the work of the devil. I do my best to avoid it in my boats b/c ethanol has issues with stability, phase separation, fuel line damage, and can be hydrophillic.

In a car used regularly, most of those are not issues.

However, ethanol blends produce less power; in theory your ecu can adjust to take advantage of the higher quality fuel.
frayed is offline  
Old 12-12-2013, 07:29 PM
  #7  
LexVan
Addict
Rennlist Member
 
LexVan's Avatar
 
Join Date: Jan 2013
Location: Chicagoland Area
Posts: 19,430
Default

I say, buy octane. 93 octane with ethanol is better than 91 octane without ethanol.

If all you can only get 91 octane, than 91 octane without ethanol would be best.

There is no more 93 ethanol free. Only 91. As far as I can tell. If they say it's 93 I'd be very suspect.
LexVan is online now  
Old 12-12-2013, 07:43 PM
  #8  
GrantG
Addict
Rennlist Member

 
GrantG's Avatar
 
Join Date: Jun 2002
Location: Denver
Posts: 9,527
Default

Originally Posted by LexVan View Post
I say, buy octane. 93 octane with ethanol is better than 91 octane without ethanol.
I disagree. The amount of power lost due to the lower energy in the ethanol fuel is greater than any gain due to the 2 points of additional octane at high altitude.

The air here has so little density (>15% less than sea level) that it lowers the effective compression enough, so that there is almost no benefit to more than 91 octane in a stock GT3.

And any added ethanol reduces horsepower noticably.

Results are different with turbocharged cars with custom tuning.

But it's a moot point, since I don't think they sell 93 octane in Colorado (even with Ethanol). It's either 91, E85 (which is 107 octane), or race fuel.

Race fuel (unleaded, non-oxygenated like the 98 octane stuff below) would be best for a new GT3 (just marginally better than the non-ethanol 91, but more than double the price)...

This is what they sell at the track:

Sunoco 260 GT 100 octane unleaded street legal 3.3% oxygen, $9.46/gallon
Sunoco 260 GTX 98 octane unleaded not street legal 0.0% oxygen, $9.51/gallon
Sunoco Standard 110 octane leaded not street legal 0.0% oxygen, $9.21/gallon

Last edited by GrantG; 12-12-2013 at 07:59 PM.
GrantG is online now  
Old 12-12-2013, 09:05 PM
  #9  
Mike in CA
Addict
Rennlist Member
 
Mike in CA's Avatar
 
Join Date: Jun 2001
Location: North Bay Area, CA
Posts: 11,865
Default

Originally Posted by GrantG View Post
I disagree. The amount of power lost due to the lower energy in the ethanol fuel is greater than any gain due to the 2 points of additional octane at high altitude.

The air here has so little density (>15% less than sea level) that it lowers the effective compression enough, so that there is almost no benefit to more than 91 octane in a stock GT3.

And any added ethanol reduces horsepower noticably.

Results are different with turbocharged cars with custom tuning.

But it's a moot point, since I don't think they sell 93 octane in Colorado (even with Ethanol). It's either 91, E85 (which is 107 octane), or race fuel.

Race fuel (unleaded, non-oxygenated like the 98 octane stuff below) would be best for a new GT3 (just marginally better than the non-ethanol 91, but more than double the price)...

This is what they sell at the track:

Sunoco 260 GT 100 octane unleaded street legal 3.3% oxygen, $9.46/gallon
Sunoco 260 GTX 98 octane unleaded not street legal 0.0% oxygen, $9.51/gallon
Sunoco Standard 110 octane leaded not street legal 0.0% oxygen, $9.21/gallon
I'm not a fan of ethanol for a number of reasons, and I'd agree that, given a choice, non-ethanol gas is definitely preferable. The OP should buy non-ethanol if it's available and is competitively priced.

But the math suggests that the difference between non-ethanol and an approximately 10% ethanol blend isn't very significant. Ethanol contains 34% less energy per unit than gasoline. But since it makes up only around 10% at most of each blended gallon of normal gas, the overall reduction in energy content is only around 1/10th of that, or about 3%.

Maybe if the seat of one's pants is really educated it would notice, but I doubt most people could tell the difference. I realize the effect might not be exactly linear, but a 3% reduction in power would make a difference in the 0-60 time of a GT3 of about .1 of a second. Probably not noticeable in any situation on the street.
Mike in CA is offline  
Old 12-12-2013, 09:20 PM
  #10  
jumper5836
Super User
 
jumper5836's Avatar
 
Join Date: Mar 2004
Location: great white north
Posts: 8,130
Default

I have non ethnol gas available and from watching fuel consumption. I see better mileage with non ethnol fuels. I have a theory that they mandate (here in Ontario) gas to contain ethnol not to be green but so that you burn more fuel so they can collect the taxes on it.
jumper5836 is offline  
Old 12-12-2013, 09:39 PM
  #11  
CAlexio
Super User
 
CAlexio's Avatar
 
Join Date: May 2013
Location: San Francisco, CA
Posts: 8,165
Default

Originally Posted by jumper5836 View Post
I have a theory that they mandate (here in Ontario) gas to contain ethnol not to be green but so that you burn more fuel so they can collect the taxes on it.
You might also enjoy the brake caliper conspiracy thread found elsewhere on this forum :-)

Last edited by CAlexio; 12-13-2013 at 12:13 AM.
CAlexio is offline  
Old 12-12-2013, 11:57 PM
  #12  
GrantG
Addict
Rennlist Member

 
GrantG's Avatar
 
Join Date: Jun 2002
Location: Denver
Posts: 9,527
Default

Originally Posted by Mike in CA View Post
I'm not a fan of ethanol for a number of reasons, and I'd agree that, given a choice, non-ethanol gas is definitely preferable. The OP should buy non-ethanol if it's available and is competitively priced.

But the math suggests that the difference between non-ethanol and an approximately 10% ethanol blend isn't very significant. Ethanol contains 34% less energy per unit than gasoline. But since it makes up only around 10% at most of each blended gallon of normal gas, the overall reduction in energy content is only around 1/10th of that, or about 3%.

Maybe if the seat of one's pants is really educated it would notice, but I doubt most people could tell the difference. I realize the effect might not be exactly linear, but a 3% reduction in power would make a difference in the 0-60 time of a GT3 of about .1 of a second. Probably not noticeable in any situation on the street.
So, you would lose 3.4% of your hp, but that assumes perfect air/fuel mixture. However, ethanol needs to burn much richer than gas, and the ECU is not going to burn the mix perfectly since it assumes gasoline, so the loss is more than 3.4%...
GrantG is online now  
Old 12-13-2013, 12:19 AM
  #13  
Mike in CA
Addict
Rennlist Member
 
Mike in CA's Avatar
 
Join Date: Jun 2001
Location: North Bay Area, CA
Posts: 11,865
Default

Originally Posted by GrantG View Post
So, you would lose 3.4% of your hp, but that assumes perfect air/fuel mixture. However, ethanol needs to burn much richer than gas, and the ECU is not going to burn the mix perfectly since it assumes gasoline, so the loss is more than 3.4%...
From what I've read, oxygenates in fuel are approaching 10%, but not in all areas, so that's why I rounded to 3%. The EPA mandates 5.6% for RFG in SoCal, for example, but refiners typically are blending more ethanol than that in some places. Given the wide use of oxygenated fuel, however, I suspect ECU's are programmed for more than one assumption re: fuel quality and are able to adapt to optimize combustion.

Bottom line, we can quibble over a few tenths of a percent one way or the other, but I still doubt that the vast majority of drivers could tell the difference on the street. That said, I blend racing fuel in my tank to get the last increment of performance when track times are important.
Mike in CA is offline  
Old 12-13-2013, 01:11 AM
  #14  
GrantG
Addict
Rennlist Member

 
GrantG's Avatar
 
Join Date: Jun 2002
Location: Denver
Posts: 9,527
Default

Originally Posted by Mike in CA View Post
Bottom line, we can quibble over a few tenths of a percent one way or the other, but I still doubt that the vast majority of drivers could tell the difference on the street.
Fair enough. So we're talking about 15 to 20 hp on the GT3. Porsche would charge $20k for that sort of bump
GrantG is online now  
Old 12-13-2013, 01:31 AM
  #15  
donuts
User
 
Join Date: Jan 2007
Posts: 135
Default

Don't forget about the fact that ethanol damages catalytic converters.
donuts is offline  

Thread Tools
Search this Thread
Quick Reply: any advantage to running non-ethenol gasoline?


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: