Has anyone done the math on how their truck performs as far as which is the cost effective choice, E85 or 87? I've done the math and depending on the price differential and the cost of the fuel itself I end up ahead or behind. I have it in an excel file, but I don't know how to upload it to rps so that I may share it with others. I might upload it to my personal website but I don't know....anyway, this is what I did:

1. Record your mpg while using 87 (19.6)
2. Record your mpg while using E85 (17.9)
3. Given a random fill up amount, let's say 15 gallons, compute the distance you would travel for both fuels
distance w/E85 = 17.9mpg*15g = 268.5 miles
distance w/87 = 19.6mpg*15g = 284 miles
4. Compute the loss in miles by using E85 instead of 87.
Distance difference = 284 - 268.5 = 25.5 miles
5. Record the cost difference per gallon between E85 and 87. In Hilliard, Ohio, the cost of 87 and E85 WAS 1.99 and 1.79, respectivly. That is a 20 cent/gallon difference.
6. Now, by filling up with 15 gallons, and at a savings of 20 cents/gallons, you are saving 3 dollars (.20*15).
7. Now, in step 4 I found that I'll go 25.5 miles LESS because I filled up with E85. Now I want to know how much MORE E85 it'll take to go that lost mileage. So I take the number of miles lost, 25.5 miles, and divide that by my mpg with E85, 17.9mpg.
25.5/17.9 = 1.42 gallons
8. Now, to buy those extra gallons (1.42gallons of them) of E85 at a cost of 1.79dollars/gallon, that comes out to 2.55dollars = 1.79dollars/gallon * 1.42gallons
9. Now, since I saved 3 dollars by filling up with E85 instead of 87, and it'll cost me 2.55 to make up the loss incurred by the poor fuel economy. So, I saved 3, but had to spend 2.55 more to go the extra distance. This means by filling up with E85 at a cost differential of 20 cents per gallon for a 15 gallon fill up, I save 45 cents.

I know this seems silly...all this math to show you I saved 45 cents, but I'm an engineer and I thought it would be interesting to do a cost breakdown of the trade off between the loss in fuel economy by using E85 and the savings at each fill up.

Now, mind you, I put this crap into excel and now my savings by filling up with E85 are hosed because now 87 is around 2.49 and E85 is 2.29 (I think). But the cost of fuel is different all over the country so maybe this will help someone else out.

C

Interesting stuff...of course with all the changing prices I'd have to redo the math. Also, the nearest E85 is 40 miles away, which also adds a lot of cost...

Yes, that is true, you would have to redo the math. But if anyone would like, just post your email address and I'll forward my excel sheet to you.

Depending on the responses (if they are good), I was thinking of doing something in excel or matlab and coming up with some plots of cost differential versus savings.

C

What are you trying to save?
...the Planet? Go E85, lower emissions.
...the USA? Go E85, Ethanol is mixed with domestic fuel, so less money goes to the Middle East (Despite the fact that Canada provides most of our gas).
...some money? Sux, but you have to do the math. And, if it's only $0.45 a TANK, is it worth the time and effort of the math and spreadsheets? I know, I do it too, that is my Obsessive Compulsive trait too. I would use E85, just to keep money flowing in that direction. I'm a big alternative fuel person, I just like having options. If people, such as yourself, stop buying E85, it won't be on the market long...

If you have access to E85 and wish to use it exclusively, you can bump your compression up to 12:1 and pick up the lost efficiency getting the same MPG as 87 octane and saving over $3 per tank. Now, if you are an economics major, you know that the cost of the rebuild will blow away that savings, but come on, you know you want to do it anyway! :E

The way I see it is if this is going to help the US economy and less profit is going to the middle east I don’t care if E85 is more expensive than 87. I only wish E85 was available in my area hopefully it will be soon because aren’t most cars and trucks especially new GM‘s E85 capable?

SY4.0, you do realize that 80% of our fuel comes from Canada and Mexico right?

20% going to the middle east yes, but still not worth it, economies of scale if you look at it economically, people will buy cheaper, the majority anyways.

Not quite...
The "Americas" account for 58% of our imports.
25.2% comes from "middle eastern" countries or countries sympathetic to the middle east. That's crude and all petroleums.
Top 15 imports (in order)
CANADA, MEXICO, VENEZUELA, SAUDI ARABIA, NIGERIA, ALGERIA, IRAQ, ANGOLA, ECUADOR, VIRGIN ISLANDS, RUSSIA, NETHERLANDS, NORWAY, COLOMBIA, UNITED KINGDOM

Now 40% of the oil we use is 100% domestic, so 60% is "foriegn". That means of that 60%, 58% (or 34.8% total) is from the "Americas" and 25.2% (or 15.2% total) is "middle-eastern". 10% of our total is from "other" countries.

BTW I'm researching a paper on this very subject... :E

I wish E85 was availible in california, but as far as my research has led me, The EPA is reevaluating the way stations handle E85, and their not sure if it is hurting the environment. I don't understand how California, land of not hurting the environment has a problem with E85!! Unbeleivable.

Anyways, someone on TRS was posting on this exact thing, he posted his MPG with both fuels, and the cost of both, and thought he was doing worse with E85, but I did the math the same way it was dne here to show him, he was actually saving $0.15 running E85, LOL!!

The issue is California is still bitter about MTBE. They proved it causes cancer and petitioned the US Govt to drop the MTBE requirement for CA. The feds declined (Mostly due to NAFTA Agreements and the parent company that makes MTBE is in Canada and planned to sue!) so CA did a study to see if E10 could be sold as "regular" fuel instead. The E10 had reduced polutants, but had equal or higher VOC's, yet another issue...

....aren’t most cars and trucks especially new GM‘s E85 capable?GM is doing a big advertising push right now but the truth is that Ford, GM and other manufacturers have been offering FFV E85 capability on selected models for several years. Which powertrains are FFV's changes from year to year. Certain 3.0L Ranger models (not all) have been FFV's in the past but that program was discontinued after 2003, IIRC.

Not all vehicles are E85 compatible. Not even a majority are. Not Fords, not GM's, not any other nameplate sold in the U.S.

Ethanol FFV's require a different PCM calibration and ethanol resistant fuel system components. The calibration and fuel system in your 4.0L is not compatible with E85.

For 2006, Ford offers E85 FFV capability for selected powertrains of the following models:

Taurus
Crown Victoria
Grand Marquis
Town Car
F-Series

I did the math on my 1999 ranger with e-85. My gas mileage went down 14% and presently the cost differance is less than 14%, so its a bit more expensive.

BUT when it is below zero outside, the e-85 is a better fuel.