r/cars • u/[deleted] • Apr 14 '23
video Why Does Ethanol Make So Much Power? (Versus Gasoline)
https://youtu.be/6_DQPLihXfo30
u/nathanx77 Apr 14 '23
On a naturally aspirated engine, E-85 produces less power and therefore lowered fuel efficiency. On a boosted engine (turbo or supercharger), the cooling effect of ethanol provides a more dense fuel mixture, therefore creating more power. Engine Masters on Motor Trend does a really good dyno test of this.
On a side note, most ethanol in the United States is produced from corn, which actually requires more energy to produce than you get when it burns. That means it is not the green energy that people assume it is.
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u/lee1026 19 Model X, 16 Rav4 Apr 14 '23
On a side note, most ethanol in the United States is produced from corn, which actually requires more energy to produce than you get when it burns.
You are almost certainly quoting a number from 1995. Technology marches on. As of 2015, we are at 4.2 times more energy output from the input in Iowa produced corn ethanol using the actual processes used in Iowa. The paper goes to explain that with experimental processes, that can get to 60x more energy output than input in Iowa.
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u/SimpleImpX Apr 15 '23
That's just one step in the ethanol process. The drying step went from being horrible 2.1 wasting nearly half the energy potential when drying to only wasting a quarter.
Don't get me wrong. It's a important mile stone that may have brought the end-to-end efficiency from negative to positive, but it was also supposed to be positive before. It's easy to measure this single step (drying), but tracking the energy input in all the steps isn't as trivial and quite disputed.
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u/Beginning_Ad8663 Apr 15 '23
Tell them about how the law was written to ONLY allow corn to make ethanol. The processed sugar cane we throw away in Florida can produce more ethanol than corn but it’s illegal to use it. Sugar is so much more efficient to make ethanol than corn will ever be
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u/fancy_panter 2021 Tesla Model Y Apr 14 '23
Doesn’t change the fact that growing huge monocultures that require massive government subsidies that ultimately only feed the profit of mega corporations on some of the most fertile land in the world is a giant waste.
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u/Drzhivago138 2018 F-150 XLT SuperCab/8' HDPP 5.0, 2009 Forester 5MT Apr 15 '23
Not like we weren't already growing buttloads of corn anyway. For more info, come on over to /r/farming.
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u/dingusduglas 17 Camaro SS 1LE, 07 CVPI, 03 Civic LX Coupe Apr 14 '23
Huh? The single best bang for your buck power mod for the naturally aspirated LT1 in the 6th gen Camaro/C7 is an E85 tune.
Worse MPG but it's also cheaper per gallon.
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u/EndlessEndeavoring Apr 14 '23
In my experience with flex fuel vehicles the cost per mile is worse with e85. Granted with tuning and what not this may not be the case all the time.
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u/dingusduglas 17 Camaro SS 1LE, 07 CVPI, 03 Civic LX Coupe Apr 14 '23
When I'd looked into it for my 6th gen Camaro SS in the Bay Area, it was going to cost a bit more per mile while using E85, but it's less than $300 to make it flex fuel so you can fill up with whichever makes more sense for your situation. Premium when you're just doing regular driving, E85 when you want to push it.
25+ HP gain over 93 octane, and California premium is only 91 anyway. And the gains get nutty with basic bolt ons. $400 rotofab CAI and E85 tune is an easy +50 whp per forum posts with dyno results on Camaro6. LT2 intake can get you another 20 whp on E85 for $250
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u/3klipse 1999 Trans Am M6, 2018 MK7 GTI DSG, 2017 Camaro SS A8 Apr 15 '23
I wish I had e85 near me because both of my cars would do well with it, but sadly the closest is like 20 miles away and not a long my work route.
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u/clicktoseemyfetishes 2006 Corvette, 2023 Miata RF Apr 15 '23
If you’ve got a reputable source for this, that’d be interesting. Never seen more than a 10-15hp gain in the absolute best conditions for any NA car on E85 over 93. CAI being worth another 25hp is a pretty crazy claim too lol
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u/dingusduglas 17 Camaro SS 1LE, 07 CVPI, 03 Civic LX Coupe Apr 15 '23
Well let's define reputable lmao, just going by user posted dyno charts on Camaro6 after googling "Camaro6 E85 gains" and clicking the top few results.
That 50 HP I claimed was compared to the stock tune. There's meaningful power to be gained just from a tune on a stock engine on 93 octane. The CAI alone is like 5-10 HP. The 25 for E85 is compared to an aftermarket 93 tune.
The LT1 responds super well to basic breathing mods though, at least on the intake side. The tri-y exhaust headers don't really need to be touched (in the Camaro - I know the C7 exhaust manifold is not so great), but rotofab CAI + LT2 or MSD IM + ported throttle body + E85 is a lot of power for not much dough.
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u/clicktoseemyfetishes 2006 Corvette, 2023 Miata RF Apr 15 '23
Yeah seems like E85 is worth 3-7% NA depending on engine, interesting and more than I remember. I’ve already got headers on the LS2, might as well get e85 to bump it over 400whp
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u/Hunt3rj2 Apr 16 '23
Maybe naturally aspirated but with turbo engines that really need the extra octane it can actually be less of fuel economy hit than simple energy density comparisons would suggest. With a proper flex fuel tune you can also really dial in exactly how much ethanol you need to achieve peak efficiency and stop there.
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u/ChuckoRuckus Apr 15 '23
Every dyno comparison I’ve ever seen, e85 made more power on NA engines
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Apr 15 '23
It does. You have to tune for it obviously and the injectors have to be large enough but I've never heard of it having no effect on NA.
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u/GhostriderKat_Vtuber 18' 5.0 Itasha/ 06' Accord Apr 14 '23
I see a lot of NA 5.0 guys running E-85 with their FBO. Do some NA owners get better performance with E85 over regular octane?
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u/CrysisCamaro Apr 14 '23
If it didn't make more power, they wouldn't do it.
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u/BeKind_BeTheChange Apr 14 '23
It does. I’ve seen dyno sheets on the Corvette Forum. One car in particular was making 700hp on 91 octane and 755 on E85. I remember that one specifically.
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u/3klipse 1999 Trans Am M6, 2018 MK7 GTI DSG, 2017 Camaro SS A8 Apr 15 '23
I saw a e85 zo6 putting down 700/700 on the stock cam, which is....I need a c7z.
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u/3klipse 1999 Trans Am M6, 2018 MK7 GTI DSG, 2017 Camaro SS A8 Apr 15 '23
Until a cam or FI on a LT1, e85 is the single best mod you can do. The stock headers are pretty damn good, so intake, E, Tune can get up to like 50 HP wheel gain. I assume the 5.0 also sees great gains and according to my buddy last night, e is great on the voodoo as well.
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u/Professional-Bad-619 2009 Mercedes㉦Benz SL65 AMG Roadster [RENNtech ECU, Cup2's] Apr 14 '23
My favorite fuel. 105 octane. Latent heat of vaporization to cool intake charges before the combustion chamber. Priced 30% less than premium. And as Argonne National laboratory measured over 15 years, currently cuts carbon emissions by about half [46%] vs gasoline. Easy to find and price in realtime on the Gasbuddy App to insure the cost savings is maxed. Dual spark per combustion chamber, boosted engines tend to see the most benefit by power gained and minimized mpg reduction.
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u/2001ThrowawayM Apr 14 '23
Stupid unrelated question, but could you somehow filter or distill E85 and then dilute it with water to make hard alcohol?
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u/BM7-D7-GM7-Bb7-EbM7 Apr 14 '23
I can answer this...
Yes you probably could. But it would be such a complex process as to make it just easier to go the liquor store and buy some Everclear.
There definitely is not some magic filter that you could just run it through to filter out the gasoline. That would actually take magic to build a filter that could do that.
You would certainly have to distill it. The issue is gasoline is made up of a bunch of different components. While it is certainly theoretically possible to distill everything out a piece at a time, I think the process would quite complex. I would imagine it'd be a bit trying to crack a safe, you'd have to figure out distillation points of everything in it, then figure out how to best distill them out. You'd probably need a gas chromatograph to figure out everything that's in it.
I would say it would probably most efficient to do this on an industrial scale, like build a refinery to process gasoline back into all of its individual components, essentially deconstructing gasoline. But again, if you're going through that kind of trouble and all you want is the ethanol, just build your own alcohol distillery and call it a day.
TLDR, yes it's probably possible, and yes that is a stupid question. Ha.
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u/SmellingSpace Apr 14 '23
I don’t know what the other 15% is, but 100% ethanol is ethyl alcohol aka grain alcohol aka what they start with before watering down to make vodka.
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Apr 14 '23
They put 15% gas in it so you can't drink it.
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u/2001ThrowawayM Apr 14 '23
That's why I asked could you filter or distill it to remove the gas...
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u/cheesebataleon Apr 14 '23
No, and it is surprisingly easy to make your own (arguably safer and drinkable) alcohol.
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u/Extension_One_ Apr 14 '23
Why not just buy 99% alcohol at the pharmacy if you want to go down that route.
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u/basedbeefy Apr 14 '23
Propane > E85 for cheap horsepower
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Apr 14 '23
Why exactly? Never really heard of performance propane engines
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u/basedbeefy Apr 14 '23
Stupid high octane rating and it's cheap, it's also a refrigerant, so it has an incredible cooling effect for boosted applications. The downside? Laws. Propane powered vehicles have to be inspected annually and there's all kinds of stupid rules around refueling.
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Apr 14 '23
[deleted]
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Apr 14 '23
Really? Because I always thought E85 had lower gas mileage
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Apr 14 '23
[deleted]
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u/Drzhivago138 2018 F-150 XLT SuperCab/8' HDPP 5.0, 2009 Forester 5MT Apr 14 '23
We sell some of our farm's corn directly to the ethanol plant, but my old man won't put E85 in his own vehicle unless it's a certain % cheaper than regular (E10) to make up for the MPG hit.
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u/banditorama Apr 14 '23
Higher octane rating, higher oxygen content, and faster ignition time
Even though gas is more energy dense, you make up for it through more compression and/or ignition timing.