phluxx

I'm new doing a lot of reading trying to learn so bare with me.

E50 = 50% ethanol 50% high octane pump fuel

E85 = 85% ethanol 15% high octane pump fuel

and so on.

I'm feeling like this is a stupid question but this comes pre mixed with the high octane pump gas already in it correct? otherwise they couldnt call it E50 or E85 ? it would just be E100 without high octane pump gas?

and if someone wanted to make their own blend and only had access to E85 but wanted to make it E50 say, would they just add more high octane pump fuel (94) to it to even out the ethanol to fuel ratio?



also does anyone test their fuels for ethanol content or just "trust" their suppliers I feel trusting supplier when your cars tuned for a specific ethanol content is a dangerous assumption?



Thanks for all replies and help

G Atsma

The gasoline mixed with ethanol is NOT necessarily high octane. The ethanol is being used to raise the octane. The number on the label, like "E85" IS the ethanol content.

phluxx

So how would one make their own mix ? just any brand chevron,esso, shell high octane mixed with less e85 if that makes any sense?

G Atsma

I don't know the octane of E85 since it is not sold around here, but it's a matter of figuring averages. Which octane are you looking for?

phluxx

well highest octane possible i guess with the least amount of load/duty cycle on my injectors they will be deka 80s.


from what I understand there is no significant benefit of E85 over E50. They're more or less the same octane rating, same detonation resistance/ anti knock and have the same cooling properties. So why bother wasting injector duty cycle on e98/e85 when you could get all the same benefits with less injector strain ?

seems like E50 is the way to go. On top of less injector strain you have more pump gas to ethanol ratio make it better on fuel miles to a tank wise and less ethanol content which means its not as hard on your fueling system ?


Im learning and reading a lot my brain is mush please correct me if i'm wrong so I know.

here's a chart I got from Fear LS thread.


Thanks for all help and replies

G Atsma

You are welcome! I am not very knowledgeable about E85, just that it's 85% ethanol! lol
The ONLY benefit I can see about it is the higher octane, as the mileage with it SUCKS! Literally.... lol

baronsmith98

iTrader: (2)

Interested in the advantages in the e50 vs e85 debate. If I can get away with e50 that would be great

NicD

iTrader: (7)

Let's not forget the higher oxygen content of E85 vs E50. Sure E50 has a similar MON/RON/antiknock as E85 but it doesn't have the oxygen content. If you want to make more power you use more ethanol, but of course this all depends on your combo and how aggressive it is and if you can really take advantage of it.

stevieturbo

Has it not been fairly well covered...that E85 doesnt necessarily mean 85% ethanol ?

Some seem to suggest that is a maximum, and those testing have reported much lower numbers, and it can vary winter/summer too, and gas station to gas station.

Hell, even those who I've seen test VP E85 report back at around 70%.

As to what makes up the other percentage, that's a guessing game !

01ssreda4

iTrader: (96)

I would buy an E test kit and practice. Ours blends run about 70% year round here. I would buy 5 gallons of e70, splash one gallon of 87 octane in it, and see what it lowers the percentage to. I wouldnt trust some internet formula I dont think, I'd have to see for myself.

pantera_efi

iTrader: (1)

Hi ALL, I DO KNOW, as my first experience was a Tech Inspector for Tri-C KARTING before Tim Woose/Berry Duffin INVENTED the "E" fuel blends for Union 76. (Yorba Linda R&D center 1980's)
My gauge tested the "E" / "M"" content of the race car fuel tank before the race.
I use the same gauge today to measure PUMP E-85.

First, there is NO LAW as to the "E" content of pump E-85 with changes from E-70 TO E-85 as common.
Second, the PUMP GAS in CA. = E-10 as does NASCAR specified fuel.
Third, the LOWEST GRADE, the trash, petrol is the one chosen to blend with Ethanol for pump gas.
Fourth, Pump E-85 likes the ignition timing of pump hi test fuel.
Fifth, I HAVE measured VP E-85 as correct for "E" content.

Bottom line, do NOT trust.

The "blend" of pump High Test/E-100 would be the better choice AND the/your "E" content would the same for the fuel calibration.

This IS the reason that Flex Fuel Sensors are required.

Lance

phluxx

Thanks for the write up Lance. For a gen 4 5.3 your recommendation would be E98 mix with 5%"race gas" ? ( race gas same as avgas or different? )
goal is 700-800RWHP



In this scenario ill need a lot of injector I'm assuming because of the ethanol content ? I don't think deka 80's will get me there, probably need bosch 210s ?


what happens if I pickup said E98 and the enthanol is below 98%? when its above and I want to lower all I need to do is add any gas station low grade pump gas easy enough, but what about when its the other way around and i need to add more ethanol ? Do I buy a pail of 100% and add according ?

and is this the tester your talking about ?

pantera_efi

iTrader: (1)

Hi Plux, thanks for the kind words.

Your AV gas question : Use 100-130 Low Lead as fine with a GOOD Price found as common.
THUS first question = YES

Your second question is about Fuel Injectors : I sell the Ford/Bosche 160 S/S Alt Fuel injectors OFTEN for E-95 use at YOUR HP Level.
This fuel injector has Stainless Steel internals @ $105.00 each USD.

Your "blend" question is NOT a meaning of understanding of what I state.
I state, Tim Woose states, "A small amount of leaded, high octane, fuel will EXTEND engine life by adding lubricity."

My tester was purchased at a Karting Shop (GO Kart) AND is electronic.

Lance

JoeNova

Run a GM flex fuel sensor.

01ssreda4

iTrader: (96)

Leaded fuel kills 02s. If you're running them.

joecar

if you really want to calculate how much E0/gasoline to add to E85 to obtain E50:

assuming they contain exactly the % they say (...yeah, I know...)

say you have a container of E85,
the fraction of E100 is 0.85, and the fraction of E0 is 0.15,
now, to the volume of fuel in the container, you add some fraction x of that volume of E0 to it;
so now the E100 fraction is 0.85/(1+x) and the E0 fraction is (0.15+x)/(1+x),
you want the E100 fraction and the E0 fraction to each end up at 0.5,
so solve both of those simultaneously:
E100 fraction: 0.85/(1+x) = 0.5
E0 fraction: (0.15+x)/(1+x) = 0.5
( taking care that the E100 fraction and E0 fraction together add up to 1 )

you will see that x has to be 0.7 to satisfy both equations;

i.e. to the container of E85, add 70% more E0

e.g. say you have 10 gal of E85 in a container,
this consists of 8.5 gal E100 and 1.5 gal E0,
now add 7 gal of E0 to this container (avoid spillage),
now you have 8.5 gal E100 and 8.5 gal E0,
by definition this is E50.

joecar

and if you do mix your own, test the % of both components before mixing, and adjust the equations and solve again...

and test % of the resulting mixed solution.

joecar

It's even simpler than I thought, simply just look at the fractions directly:

to bring the E0 component from 0.15 to 0.85 (to equal the E100 component's fraction) you have to add 0.7... simple.

JoeNova

Or you can just run a GM flex fuel sensor and a flex compatible PCM, and never have to measure or retune for ethanol % no matter what it ends up being.

phluxx

I like this idea, it would make life much easier. I feel like you'd be sacrificing potential performance though ? running the flex sense would adjust accordingly but from tank to tank you'd be making more or less power?