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93 with 10% ethanol vs 91 ethanol free

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Old 06-07-2019, 07:17 PM
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93 with 10% ethanol vs 91 ethanol free

I see a lot of different opinions with this ethanol stuff. Right now my car is fine tuned running the 93 with the 10% ethanol. Would there be any good reason to run 91 ethanol free? Would I need to adjust my tune? Would I even see a performance increase with the non ethanol?

Pretty sure the car would run on 91. 427 SBC. AFR 220'S, XR294HR, HSR, 10:5:1 compression.

Just looking for opinions if it's even worth trying. Thanks!
Old 06-07-2019, 10:55 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

pretty sure these cars came with anti ethenal warnings.
Old 06-08-2019, 10:06 AM
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Re: 93 with 10% ethanol vs 91 ethanol free

I don’t know if the 10% is enough to really do any damage. I’ve been running it for over 10 years with no issues.
Old 06-08-2019, 11:37 AM
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Re: 93 with 10% ethanol vs 91 ethanol free

If you have new fuel pump it shouldnt be a problem. I really doubt there would be much difference in power or drivability between the two. Is 91 cheaper? It could be a good experiment lol

if anything the ethanol should cool intake air temps at the moment of injection and should make more power. But nothing drastic maybe 1-4 ponies lol. I know quite a few cars make bit more power on e85 no other changes vs 93. Tribute that to air cooling. But its not much. 10 15 hp on some hot setups
Old 06-08-2019, 12:00 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

My mechanic told me once that the ethanol is what really kills the old injectors and the ethanol gas does not have a long shelf life as well. I have a few stations near me that still have 91 non ethanol and that’s what I run in my GTA and all small engine stuff.
Old 06-08-2019, 12:19 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

E10 has been pretty much the only thing you could buy around here for like 20-25 years.
Old 06-08-2019, 12:30 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Thanks for the replies guys. I read an article a while back saying you will make more power using non ethanol gas. I honestly haven’t done a lot of homework on it. Just wanted your guys opinion.

The non ethanol is more expensive. Sounds like it’s not worth my time. Heh.
Old 06-08-2019, 12:43 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Have you dynoed that combo? Curious how it does. I’d be more inclined to go e85 if you are chasing few extra ponies but it does requires good fuel system components and such. Larger pump injectors etc. ptfe line
Old 06-08-2019, 01:37 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by Orr89RocZ
Have you dynoed that combo? Curious how it does. I’d be more inclined to go e85 if you are chasing few extra ponies but it does requires good fuel system components and such. Larger pump injectors etc. ptfe line

I haven't. No track times either. I'm slacking super bad. That's what I get for getting married and buying a house shortly after I got that engine in, lol. I've had hawks 17" rims and brand new tires sitting in my garage for months also. The car feels very fast. But I'm not certain it is a 10 second car. I will say after burning chips for the last 5 years. The tune is dialed in.
Old 06-27-2019, 11:11 AM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by IROCThe5.7L
I see a lot of different opinions with this ethanol stuff. Right now my car is fine tuned running the 93 with the 10% ethanol. Would there be any good reason to run 91 ethanol free? Would I need to adjust my tune? Would I even see a performance increase with the non ethanol?

Pretty sure the car would run on 91. 427 SBC. AFR 220'S, XR294HR, HSR, 10:5:1 compression.

Just looking for opinions if it's even worth trying. Thanks!
Main difference would be the AFR reported on WBo2 and possibly adjustment of VE tables. If assume Stoich of E10 is approx. 14.2:1 .vs. 14.7 for straight gasoline, then Stoich differs by 3.4% [1-(14.2/14.7) = 3.4%].. So yes, tune would be changed, If properly tuned with E10, AFRs will be 3.4% higher with straight gasoline. That's why Lambda tuning always preferable to using AFR (1 Lambda always Stoich regardless of fuel type).
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Old 06-27-2019, 02:22 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Note that testing the ETOH content of fuel is easy and a good idea. Several years ago I was doing this on a regular basis and found that it was all over the place. At that time Sunoco 93 Ultra had no ETOH in it.

While other fuels at 87 & 89 octane ran between 3% and 7%.

I should do some additional testing just to keep up with it.

RBob.
Old 06-27-2019, 06:13 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by RBob
.. . .While other fuels at 87 & 89 octane ran between 3% and 7%.RBob.
Absolutely do!!!
Old 08-08-2019, 04:39 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

OK, picked up some Sunoco Ultra 93 fuel last week. Tested today at 0% ethanol.

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Old 08-08-2019, 08:03 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by RBob
OK, picked up some Sunoco Ultra 93 fuel last week. Tested today at 0% ethanol.

RBob.
What part of the country are you from?
Old 08-08-2019, 08:21 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

This is very interesting. I use the Sunoco 93 in my bird also. How do you test for ethanol?
Supposedly only Missouri and Montana have ethanol free high test gas.


Louis



Last edited by Ct1987; 08-08-2019 at 08:30 PM. Reason: typo
Old 08-08-2019, 08:27 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

For years I thought Sunoco 94 up here was the bee’s knees. More recently I’ve learned (pretty sure) that for a few years now it and every other grade is 10% ethanol
Old 08-09-2019, 06:35 AM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by chazman
What part of the country are you from?
SE corner of Pa.

RBob.
Old 08-09-2019, 06:44 AM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by Ct1987
This is very interesting. I use the Sunoco 93 in my bird also. How do you test for ethanol?

Louis
It is easy, I use a 10 ml graduated cylinder. Place 1 ml of water followed by 9 ml of gasoline to be tested. Cap and gently shake. Let the solution settle and look to see if the water level rose above 1 ml. If no change in the water level, 0% ETOH.

The amount of increase over 1 ml shows the amount of ETOH in the fuel.

Briggs and Stratton along with many other companies sell test setups for ethanol content. A boat shop/store will also likely carry a tester.

RBob.
Old 08-09-2019, 08:11 AM
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Re: 93 with 10% ethanol vs 91 ethanol free

Originally Posted by RBob
SE corner of Pa.

RBob.
Wish that gas was available around here!
Old 08-10-2019, 07:23 PM
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Re: 93 with 10% ethanol vs 91 ethanol free *******

Hi everyone,

I went to my local Sunoco station today and filled up my Bird with the 93 octane.

I also took a quart sample to test at home. I did the bottle test and the 93 octane does not have any ethanol at all.

What I find very interesting is that the station pump has no sticker on it anywhere, that says that it contains 10% ethanol.

I would assume that the other octanes also were ethanol free.

I pulled into two other gas stations, one a Shell and the other Cumberland farms and their pumps had big stickers telling the world that this fuel contains 10% ethanol.

So, I don't know how they get away with this. This has been a well guarded secret. till now. In case you are wondering, I am in the Northwest corner of Connecticut.
I am going to one of the bigger cities tomorrow and will check two more Sunoco stations to see if their pumps are free of ethanol stickers. This is really good news.

Louis
Old 08-11-2019, 01:22 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

Good deal. I've also been using the Sunoco Ultra 93 in the small engines (mowers, string trimmer, chain saw, and so on). As ethanol affects the carbs in them.

RBob.
Old 08-11-2019, 07:47 PM
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Re: 93 with 10% ethanol vs 91 ethanol free

I took a ride today to Waterbury, ct, about 20 miles south from me. I checked 3 Sunoco stations and all 3 had the 10% Ethanol sticker on the pump. I spoke to a person knowledgeable on this subject and he said that all gasoline comes to Connecticut via the port of New Haven. All gas comes from the refinery as pure gas. Its at the distribution terminal that Ethanol is added to the gas. He said that its at the discretion of the distributor if Ethanol is added and what amount. As inspector Clouseau would say, "I am so con fused"

Louis
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