[TRADERMIKE 2012]

Originally Posted by 78w72

thats very true. but what happens when you increase the volume of ethanol to compensate for the lower BTU? i have never had an engine set up for that but i know some people that do & most say ethanol has some benefits like cooler & cleaner burning etc. for high compression or turbo/forced induction engines the higher octane E85 is what lots of guys use. plus its cheaper than any comparable octane fuel.

as you mentioned, i have never really noticed a difference in 91 straight gas vs 93 with 10%E in 3 different pontiac engine cars, the higher HP one at the drag strip or driving any of them around town. i try to stick with straight 91 but will get the 89 or 93 ethanol if its cheaper.

Mikes Reply:

Living in south Florida on a cool night in the winter the 1967 428 HO loves the higher 93 octane with 10 % Alcohol but the next day it is 90 degrees and the Alcohol takes affect and starts vapor lock issues. Then I have to go to the Rec- 89-90 fuel, less Alcohol.

[78w72]

Originally Posted by TRADERMIKE 2012

Mikes Reply:

Living in south Florida on a cool night in the winter the 1967 428 HO loves the higher 93 octane with 10 % Alcohol but the next day it is 90 degrees and the Alcohol takes affect and starts vapor lock issues. Then I have to go to the Rec- 89-90 fuel, less Alcohol.

your engine vapor locks at 90f?? even with all the cooling mods, phenolics & heat wrap? if so, something somewhere is not right...

[Scott65]

Originally Posted by 78w72

your engine vapor locks at 90f?? even with all the cooling mods, phenolics & heat wrap? if so, something somewhere is not right...

Please don't provoke the thread killer

[AG]

Tuning with an air/fuel ratio meter is tuning by BTUs or energy content of the gas you are using.

[GoreMaker]

For sure ethanol has properties that allow an engine to make more power without detonating, when tuned for it. Higher detonation resistance, and an extra cooling property that helps prevent heat buildup. On a Buick turbo V6, we can run some absolutely insane boost on E85, but it requires as much as 50% more fueling than with regular gas. That's a pretty dramatic increase. We also have the benefit of an ECU that can run different injection and ignition tables depending on what fuel is in the tank. None of that is easily achievable on a Pontiac V8.

Right now, you'll find blends with up to 15% ethanol at the pump, though 10% is most common. The biggest issue with that is the swelling it'll cause on some seals and floats if they're not ethanol-tolerant. If the carb is tuned right, it shouldn't affect idle quality enough to be noticeable.

[Formulajones]

Boost for sure works well with E85.

I had a couple friends about 15 years back that was building N/A engines using E85. Knowing that was the fuel to be used these engines were purposely built with a lot of compression. I think they were 12:1 or a little more if I remember correctly, pretty radical camshafts, carbs setup for E85 and ran strictly an E85 diet.

They ran extremely strong but the problem was E85 availability. It wasn't everywhere then and it's still not everywhere now. That really limited the distance these cars could travel and basically remained around the town where the E85 pumps were, because regular pump gas for these engines at that point wasn't an option anymore.

[Formulajones]

Originally Posted by GoreMaker

. If the carb is tuned right, it shouldn't affect idle quality enough to be noticeable.

Yep, In the grand scheme of things 10% really isn't all that much anyway.

[TRADERMIKE 2012]

Originally Posted by Formulajones

Yep, In the grand scheme of things 10% really isn't all that much anyway.

Mikes Reply:

10% Alcohol in the fuel is all the difference in the world in my case, any Alcohol in my fuel on a hot day will cause my engine to vapor lock.

[Scott65]

[QUOTE=GoreMaker;6353234]For sure ethanol has properties that allow an engine to make more power without detonating, when tuned for it. Higher detonation resistance, and an extra cooling property that helps prevent heat buildup. On a Buick turbo V6, we can run some absolutely insane boost on E85, but it requires as much as 50% more fueling than with regular gas. That's a pretty dramatic increase. We also have the benefit of an ECU that can run different injection and ignition tables depending on what fuel is in the tank. None of that is easily achievable on a Pontiac V8."
It's not easy, but it can be done. I'm happy to be able to mix E85 and regular unleaded with gas prices through the roof...

[Formulabruce]

[QUOTE=Scott65;6353303]

Originally Posted by GoreMaker

For sure ethanol has properties that allow an engine to make more power without detonating, when tuned for it. Higher detonation resistance, and an extra cooling property that helps prevent heat buildup. On a Buick turbo V6, we can run some absolutely insane boost on E85, but it requires as much as 50% more fueling than with regular gas. That's a pretty dramatic increase. We also have the benefit of an ECU that can run different injection and ignition tables depending on what fuel is in the tank. None of that is easily achievable on a Pontiac V8."
It's not easy, but it can be done. I'm happy to be able to mix E85 and regular unleaded with gas prices through the roof...

The price IS deceiving. Ethanol has just POOR fuel economy. Engines work harder to do the same work, which means more rpms, and more heat ( in a street engine). Also consider that its subsidized by the taxpayers, so while it may seem cheaper, it just may not be.... Look at a EPA sticker on a new car. Cruising ranges are listed with E10 and then E85... Its a real eye opener. Almost has "Range anxiety"

[Formulajones]

[QUOTE=Formulabruce;6353396]

Originally Posted by Scott65

The price IS deceiving. Ethanol has just POOR fuel economy. Engines work harder to do the same work, which means more rpms, and more heat ( in a street engine). Also consider that its subsidized by the taxpayers, so while it may seem cheaper, it just may not be.... Look at a EPA sticker on a new car. Cruising ranges are listed with E10 and then E85... Its a real eye opener. Almost has "Range anxiety"

Yep, stoich for E85 is 9.7:1 so it's an extremely rich mixture, plus it takes a fair amount of compression to take advantage of it, which new cars really don't have enough of anyway making them even less efficient on that stuff.

[w72]

Mike, I live a half mile from that same train track. It's an unspoken rule in Memphis that we never discuss the fault line, and if we accidentally think about, we drink till we forget about it.

[Jay S]

I see the OP’s options were 91 no ethanol and 93 w/ethanol. I was thinking just the opposite. In that case, I would not move up to 93 unless it was required.

We don’t get to choose the blend of 91 here at my small towns. Usually if a town has 3 stations, only one station will carry 91, and most often it is a ethanol blend. 93 is becoming further and further away. I just looked and the station that had it closest to me (45 miles) is now dropped to 91. I don’t even know where I would go for 93 now.

[Dragncar]

You have not been through a earthquake until you see chunks of firewood bouncing 4" in the air and flipping over in your backyard. I was at work one time when we had three 7.2s in one day. The chain on the green chain was clacking, catching a little air when the first one hit. That night there was a light post outside my bedroom window. You seen it, then you did not see it, over and over.
Makes you feel like a insect.

[Nobuddy]

FYI - There are no federal subsidies or tax incentives for ethanol. There are federal mandates for required volume of renewable fuels which does force the oil companies to use ethanol since it seems to be the best solution.

There are long standing tax incentives for petroleum production which to some degree does affect taxes or the national debt and inflation.

[GoreMaker]

There's farm subsidies for growing corn that gets used for ethanol. From research over the years, ethanol corn wouldn't be profitable to grow without those subsidies. So because of those subsidies (which are entirely funded through taxes) farmers grow that instead of actual food.

But that's neither here nor there. That's a completely different discussion.

As far as E85 giving worse mileage, that's entirely true. If you're injecting 35 to 50% more fuel, then you'll get 35 to 50% worse mileage. In the turbo V6 community, we usually do it for racing purposes, then we switch back to regular fuel for street driving. Basically the same way some people will run AVgas for a day of drag racing

[Nobuddy]

Originally Posted by GoreMaker

There's farm subsidies for growing corn that gets used for ethanol. From research over the years, ethanol corn wouldn't be profitable to grow without those subsidies. So because of those subsidies (which are entirely funded through taxes) farmers grow that instead of actual food.

But that's neither here nor there. That's a completely different discussion.

It is a different discussion so probably best you not add more misinformation based on popular legend.

There are no subsidies to farmers for growing corn for ethanol. Virtually all US farmers receive some federal subsidies for almost every crop grown. But there is no difference in subsidies a farmer gets selling their corn for food compared to selling to an ethanol plant. The additional demand from the sustainable fuel mandates certainly raises the total demand and the commodity price for corn.

Full disclosure, I am a farmer although no corn.

[Formulabruce]

Originally Posted by Nobuddy

It is a different discussion so probably best you not add more misinformation based on popular legend.

There are no subsidies to farmers for growing corn for ethanol. Virtually all US farmers receive some federal subsidies for almost every crop grown. But there is no difference in subsidies a farmer gets selling their corn for food compared to selling to an ethanol plant. The additional demand from the sustainable fuel mandates certainly raises the total demand and the commodity price for corn.

Full disclosure, I am a farmer although no corn.

I have relatives that grow Corn Exclusively. Yes, in fact they Do get Federal subsidies to grow corn. This covers a few things which could be used for other types of farming, but It IS in fact Subsidized. 100% of this corn is sold to Ethanol plants. Subsidies make it worth Farming. I suspect they will go up as the cost if Nitrogen does.

[Jay S]

There is a .45 cent per one gallon tax credit for fuel blenders to blend ethanol with gasoline. There are no direct subsidies to farmer’s to grow corn for ethanol any more than there is to grow anything else. The reason corn gets planted and used for ethanol is do to the demand from the RFS.
Here a list of all the specific federal energy subsidies.
https://afdc.energy.gov/fuels/laws/ETH?state=US

Run what ever fuel your car likes. I have never seen a disadvantage to running 93 octane over 91 octane. If it is with in the budget, and can buy it local, i definitely suggest using 93. Should be no problem dropping back 91 if need be for part throttle cruising until you can get back to your local 93. IMHO. 93 straight gasoline is a better fuel than any of the lower octane fuel no matter what the mix. Especially for guys who’s car sits more than it gets driven.

[Formulabruce]

Originally Posted by GoreMaker

There's farm subsidies for growing corn that gets used for ethanol. From research over the years, ethanol corn wouldn't be profitable to grow without those subsidies. So because of those subsidies (which are entirely funded through taxes) farmers grow that instead of actual food.

But that's neither here nor there. That's a completely different discussion.

As far as E85 giving worse mileage, that's entirely true. If you're injecting 35 to 50% more fuel, then you'll get 35 to 50% worse mileage. In the turbo V6 community, we usually do it for racing purposes, then we switch back to regular fuel for street driving. Basically the same way some people will run AVgas for a day of drag racing

EXACTLY ! I should have said Corn subsidies, which IS ethanol.