Mixing e85 and premium fuel?

[lamrith]

http://www.intercepteft.com/calc.html

Since that site is down now, I have been searching for another way to calculate.  found a couple online calculation sites, this one seemed nicest.  limitation though is that it is whole gallons only, not decimals.
http://www.georgebelton.com/E85Calculator.php

This one lets you use decimals, but it clears out the data you entered every time you calculate, so you have to remember it and reenter gallons every time.
http://www.wallaceracing.com/ethanol-mix-calc.php

 

[TopherSho]

I need to learn to make apps  

here is the spreadsheet i built based on the wallace racing results.


whoops.. broke it. brb.

 

[TopherSho]

Fixed.

converting to CSV removed the formulas .. zipped up the XLS instead.

 

[FoMoCoSHO]

Lamrith, did you get my email?

 

[lamrith]

Lamrith, did you get my email?

Yup, thanks!!  I replied, did it not get back to you?

 

[FoMoCoSHO]

Yeah, I finally got it.

Or maybe I just didn't have enough coffee and missed it initially?

 

[lamrith]

So here is a question for the nerds among us...  Both the calculator spreadsheets work great as does the link above.

What I wonder is if anyone can figure out (or already has) a formula that will tell you the amount of each fuel to use to make a certain blend at a certain total gallons?

So I have:
92 Octane E10
100octan E85
I want to make a total of 16gallons of E30, how much of each....  (This one is easy and I know answer already, but would like to be able to quick calc on the fly based on total gallons.

We can do it by manually adjusting the gallons in each cell, but there has to be a formula that will spit out the numbers?  Probably two formulas, but that could both reference a single total gallons cell.

 

[lamrith]

Well I just did some rough playing around with the spreadsheets.  Since we are normally looking at a fixed end mix and gallons, I broke it down to ratios of the total.

For 16Gallons of E30, you need 4gal of E85 and 11gal of E10.  So when mixing E10 and E85, to get E30 you need 26.6666667% of the total gallons to be E85 and the rest is E10.

• So for 7.5gal of E30 it is: 7.5*0.266666667=2gallons of E85.  7.5gal-2gal=5.5gal of E10

To make E20 based on the same total of 15gal it takes 2 Gal of E85 and 13gal of E10.  So the ratio of E85 is 13.3333333477778% of the total volume.

• So for 7.5gal of E20 it is: 7.5*0.133333333477778=1gallons of E85.  7.5gal-1gal=6.5gal of E10

This is far from perfect way to do it.  If you do not have E85 that is actually 85% (falling short and is actually 83, etc) then this will not be correct.  That is why I was hoping someone could work up a formula to do it on the fly to account for variances.

 

[f8tlSHO]

I used the spreadsheet fomocosho gave me, got an ethanol tester to check my e85. I made up 2 cheat sheets. One for 70% one for 75%. I normally fill up when my light comes on, 5.25 gallons e85 9.75 gallons e85 to equal 16 gallons. But I have the mixtures all figured out all the way to just adding 5 gallons of total fuel. I just keep these sheets in my car laminated.


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[hawkeye93]

I use the "E85 Mix Calculator" app on my (Android) phone, works great.  From Kenny Nissel.

 

[lamrith]

I used the spreadsheet fomocosho gave me, got an ethanol tester to check my e85. I made up 2 cheat sheets. One for 70% one for 75%. I normally fill up when my light comes on, 5.25 gallons e85 9.75 gallons e85 to equal 16 gallons. But I have the mixtures all figured out all the way to just adding 5 gallons of total fuel. I just keep these sheets in my car laminated.


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Yeah I am tinkering with those sheets too.    So by 70 and 75% do you mean E25 and E30, or are you saying that the E85 you are seeing is only 70 and 75%?

 

[f8tlSHO]

I used the spreadsheet fomocosho gave me, got an ethanol tester to check my e85. I made up 2 cheat sheets. One for 70% one for 75%. I normally fill up when my light comes on, 5.25 gallons e85 9.75 gallons e85 to equal 16 gallons. But I have the mixtures all figured out all the way to just adding 5 gallons of total fuel. I just keep these sheets in my car laminated.


Sent from my iPhone using Tapatalk

Yeah I am tinkering with those sheets too.    So by 70 and 75% do you mean E25 and E30, or are you saying that the E85 you are seeing is only 70 and 75%?

E85 percent, I run e30


Sent from my iPhone using Tapatalk

 

[lamrith]

I used the spreadsheet fomocosho gave me, got an ethanol tester to check my e85. I made up 2 cheat sheets. One for 70% one for 75%. I normally fill up when my light comes on, 5.25 gallons e85 9.75 gallons e85 to equal 16 gallons. But I have the mixtures all figured out all the way to just adding 5 gallons of total fuel. I just keep these sheets in my car laminated.


Sent from my iPhone using Tapatalk

Yeah I am tinkering with those sheets too.    So by 70 and 75% do you mean E25 and E30, or are you saying that the E85 you are seeing is only 70 and 75%?

E85 percent, I run e30


Sent from my iPhone using Tapatalk

Sorry to bug you on this, just digging into it again as I consider running E30 this summer. Your comment about 70% and 75% are what are throwing me off is all.

5.25gal E85 and 9.75gal E10 would net you 16gal of E36, not E30?
Is that what you do when you convert from E10 to E30 given there are 4 Gal of E10 still in the tank so you end up with a total of 19gal of E30?

 

[f8tlSHO]

The e85 isn't 85% it's 70% in winter and 75% in summer.


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[f8tlSHO]

I used the spreadsheet fomocosho gave me, got an ethanol tester to check my e85. I made up 2 cheat sheets. One for 70% one for 75%. I normally fill up when my light comes on, 5.25 gallons e85 9.75 gallons e85 to equal 16 gallons. But I have the mixtures all figured out all the way to just adding 5 gallons of total fuel. I just keep these sheets in my car laminated.


Sent from my iPhone using Tapatalk

Yeah I am tinkering with those sheets too.    So by 70 and 75% do you mean E25 and E30, or are you saying that the E85 you are seeing is only 70 and 75%?

E85 percent, I run e30


Sent from my iPhone using Tapatalk

Sorry to bug you on this, just digging into it again as I consider running E30 this summer. Your comment about 70% and 75% are what are throwing me off is all.

5.25gal E85 and 9.75gal E10 would net you 16gal of E36, not E30?
Is that what you do when you convert from E10 to E30 given there are 4 Gal of E10 still in the tank so you end up with a total of 19gal of E30?

Here are my 2 cheat sheets


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