E-85 vs. Unleaded Break-even

[propar80]

I need a mathwiz to help me out:

Here's the information:
With e-85 I am getting about 10.6 mpg on a 27 gallon tank at $1.99/gallon.

With Unleaded I'm getting about 13.1 mpg on a 27 gallon tank at $2.75/gallon.

This is all "in-SF" mileage.

With this information...what's my break-even(I'm coming up with 52.3 cents difference in the two) where it's not worth putting e-85 in my Suburban??


I'm just not trusting my(actually someone here in the office's) math...

Good Luck and Go Jacks!! Oh, and show you're work!

[jackmd]

Re: E-85 vs. Unleaded Break-even

I got you paying 19 cents/mile with E-85 and 21 cents/mile with regular unleaded.

You say you get 286.2 miles average per tank (10.6 mpg x 27 gallons) for $53.73 (1.99 x 27) with E-85.

You say you get 353.7 miles average per tank (13.1 mpg x 27 gallons) for $74.25 (2.75 x 27) with unleaded.

Your cost for 1 mile, 53.73/286.2 = .19 and 74.25/353.7 = .21

Its about a wash with the numbers you provide. 54 cents per tank difference when talking only about mileage and cost per gallon. The way I look at it, not having to fill my tank as often is worth the extra 70-80 cents per gallon.

[UWMandSDSU]

Re: E-85 vs. Unleaded Break-even

I got you paying 19 cents/mile with E-85 and 21 cents/mile with regular unleaded.

You say you get 286.2 miles average per tank (10.6 mpg x 27 gallons) for $53.73 (1.99 x 27) with E-85.

You say you get 353.7 miles average per tank (13.1 mpg x 27 gallons) for $74.25 (2.75 x 27) with unleaded.

I get it to break even when there is a 46 cent difference.

You get 353.7 miles average per tank (13.1 mpg x 27 gallons) for $66.15($2.45 x 27) with unleaded.

Regular (at $2.45/gallon): 353.7 miles/$66.15= 5.34 miles/dollar
E-85 (at $1.99/gallon): 286.2 miles/$53.73= 5.33 miles/dollar

*using some of the same math as JackMD up above.

[jacksfaninne]

Re: E-85 vs. Unleaded Break-even

I prefer to look at it this way: with E-85, you're displacing 85% of the gasoline -- made mostly from oil from countries who don't particularly care for us -- in your tank with fuel from good ol' American corn -- made mostly from corn grown by farmers who support SDSU to the tune of millions in research dollars. So essentially, by continuing to fill up with E-85, you're supporting SDSU.

I'd take that bargain any day.

[Jacks#1Fan]

Re: E-85 vs. Unleaded Break-even

I've figured mine numerous times, and I get as good and slightly better dollar value out of E-85 as I do 10% ethanol. I don't care about filling up a little more often...what I like and am glad I do it, is that for every 10 gallons I pump, only 1.5 gallons comes out of petroleum (and usually out of imported petroleum). Works for me!

P.S. Just noticed after posting this that the previous poster (we were posting at the same time) reaffirmed what I was talking about. Brilliant minds work simultaneously (or almost!)

[CatchEmAll]

Re: E-85 vs. Unleaded Break-even

Can you repeat the part of the stuff where you said all about the...things?

[Hammersmith]

Re: E-85 vs. Unleaded Break-even

I need a mathwiz to help me out:

Here's the information:
With e-85 I am getting about 10.6 mpg on a 27 gallon tank at $1.99/gallon.

With Unleaded I'm getting about 13.1 mpg on a 27 gallon tank at $2.75/gallon.

This is all "in-SF" mileage.

With this information...what's my break-even(I'm coming up with 52.3 cents difference in the two) where it's not worth putting e-85 in my Suburban??


I'm just not trusting my(actually someone here in the office's) math...

Good Luck and Go Jacks!! Oh, and show you're work!

One of the problems is that the answer you are looking for is actually a linear function. IOW, the break-even point changes as the price of E-85 does.

Here's the equation for your vehicle:

y = 1.23585 x

where x is the price of E-85, and y is the break-even price for unleaded


At $1.99/g for E-85:

y = 1.23585 (1.99)

y = $2.46/g


Work:
y / 13.1 = x / 10.6 [cross multiply]
10.6 y = 13.1 x [divide both sides by 10.6]
y = 1.23585 x



We'll be testing this tomorrow, so do your homework.
(can you tell I filled in for a math teacher today?)

And you thought algebra was useless in day to day life. Ha!

[HoboJack]

Re: E-85 vs. Unleaded Break-even

How much you paid for the fuel doesn't really factor in since all you really need to answer the question is the fuel economy. This is simply a ratio question as the break-even point depends on the price of the fuel. 10.6/13.1 = approximately 81%. For Unleaded At $2.75 * 81% = $2.23 for E-85 is the break-even point ($.52). Anything less is a better value for E-85.

If Unleaded is $3.50 * 81% = $2.84 for E-85 ($.66 difference).

*Edit* Hammersmith esentially posted the same result. 1/1.23585 = .809169 (approximately 81%).

[zooropa]

Re: E-85 vs. Unleaded Break-even

Can you repeat the part of the stuff where you said all about the...things?

"Donuts? I said no ethnic food!!"

[1stRowFANatic]

Re: E-85 vs. Unleaded Break-even

Filbert,
Can we please have a rule about no posts where letters are used in math equations? I do not think these posters, while their intent may be innocent (we have yet to confirm this, tho) realize the harm that they can cause the fast majority of the membership of this board. Feelings of inferiority, headaches, realization of a wasted youth all can result from these types of posts. And besides, how can any of us really confirm that these posts are true? 2 or 3 posters get together and they can really cause some problems. Just a thought.

[Nidaros]

Re: E-85 vs. Unleaded Break-even

Filbert,
Can we please have a rule about no posts where letters are used in math equations? I do not think these posters, while their intent may be innocent (we have yet to confirm this, tho) realize the harm that they can cause the fast majority of the membership of this board. Feelings of inferiority, headaches, realization of a wasted youth all can result from these types of posts. And besides, how can any of us really confirm that these posts are true? 2 or 3 posters get together and they can really cause some problems. Just a thought.

Naw its okay. I liked Hammersmits review of basic alegra (Pie are square) (pun intended) and ratio and porportion is about the only math I use now days. Its assuring to know I am doing it right. Flex fuel is what I will be assured of in my next new or used car purchase. I think E85 is the future.

[rabidrabbit]

Re: E-85 vs. Unleaded Break-even

Filbert,
Can we please have a rule about no posts where letters are used in math equations? I do not think these posters, while their intent may be innocent (we have yet to confirm this, tho) realize the harm that they can cause the fast majority of the membership of this board. Feelings of inferiority, headaches, realization of a wasted youth all can result from these types of posts. And besides, how can any of us really confirm that these posts are true? 2 or 3 posters get together and they can really cause some problems. Just a thought.

And how many of the posters here are grads from the 4 fine engineering programs at State for whom this is the math that we do each day?

Letters and equations = constant :P

[propar80]

Re: E-85 vs. Unleaded Break-even

Thanks everyone for your input.

Helps me out...while I see the value to our region's economy of using e-85 all the time in my gas-hog. It comes down to dollars and sense for me. I'm hoping that my line of thinking will help push the producers of e-85 to develop fuel that gets even better gas mileage, thus reducing the "break-even" number of .52 cents. If the only reason people used it was because it was good for "our" ecomony, even though in the end it's more expensive, I don't think there would ever be any incentive to make E-85 any better.

While I like the idea of e-85 being the future(since that would be great for SD/plains), I have a feeling that in 50 years it may be looked as the "original alternative fuel" that broke down the door to alternative fuels that are even better, cleaner and cheaper like water, sun, electricity, etc. Heck, my father-in-law swears up and down that high-powered magnets can run engines if set-up properly...I think he's nuts, but on the other hand I'm sure the person who brought up putting "liquid-corn" into your vechile for the first time probably got some interesting looks also. So I guess I can't fault the guy for dreaming.

Go Jacks!!

[tjbison]

Re: E-85 vs. Unleaded Break-even

No matter what it takes Oil and Lots of it to make e-85 also, I use both and find in my GMC Pickup that E-85 around Fargo is good, but long Highway trips it isn't as I tend to Fuel up 2x and don't even think about pulling anything on e-85 WOW

[jackmd]

Re: E-85 vs. Unleaded Break-even

Filbert,
Can we please have a rule about no posts where letters are used in math equations? I do not think these posters, while their intent may be innocent (we have yet to confirm this, tho) realize the harm that they can cause the fast majority of the membership of this board. Feelings of inferiority, headaches, realization of a wasted youth all can result from these types of posts. And besides, how can any of us really confirm that these posts are true? 2 or 3 posters get together and they can really cause some problems. Just a thought.

I intentionally avoided using letters for this reason. I have the ability but didn't want to add to confusion.

However, I think I mis-typed before. Its closer to .90 per tank saved with E-85.