($/gal)/(mpg) = $/mile.

using 3.45/gal @ 18mpg = 19cents/mile
using 3.55/gal @ 23mpg = 15cents/mile

using 3.55/gal x 20gal = 71$ to fill with gas
using 3.45/gal x 20gal = 69$ to fill with e10

saved 2$.

(savings)/(cost/mi) = max distance to gas station to break even.

2$ saved/ (.15$/mi) = 13 miles.

so ... if your station is 10 miles further to find pure gas:
($2 saved) - [(10mi) x (.15$/mi)] = $0.50 saved on that tank

(savings per tank) / [(gas used) x (mpg)] = total $saved/mile
$0.50 saved / (20gal x 23mpg) = $0.001 saved per mile

$0.001 saved per mile x 200,000 miles = $217 saved over the life of the truck.

lots of assumptions on my part with the numbers, but there is your template.



looks like you can save money ..... a little at a time.

engineers are number junkies ... we can't help it .. check my math though, it's been a rough day.

 

I should add ... this assumes your time is worth nothing.

if you figgure in your time then:

10mi/60mph = .16hrs. figgure you are worth at least the minimum wage $7.45

$7.45 x .16hrs = $1.19
$2 saved - $1.50 - $1.19= -$0.69.... so saving $2 per tank could cost you $0.69if you could have been doing something more productive with your time than driving to the gas station


but at this point, we are admittedly splitting hairs

 

After seeing that, the you are pay .69 for the extra power. May be worth it, may not be, it depends on the person. I would do it, but then again I want all the power I can get.

 

This looks quite funny and quite confusing as well but thanks.

It's the same distance to the pure gas as it is to the E10 station, just opposite directions.

the E10 is 3.48 with state and fed taxes included.

The Pure is $3.18 without state and fed taxes added until you pay. When taxes are added it brings it up to $3.56 (Today)

Truck gets 23-24mpg's on E10
Now getting 26.4-27.8 on pure.

Believe it or not the road surface really effects my mileage. It varies on the road I'm on.... The smooth recently repaved roads add about 1 mpg. The really rough roads drop it as much as 2.5 per gal.

There is a place on SR60 where the road is terrible from Semi's pulling out and it drops allot in that area, everytime I go through it.


It costs me about $6 or 7 dollars more per tank to fill it with Pure gas.
I feel the extra $7 is well worth not only the extra mileage, but also the power.

I am going to try another test beginning February.

I am a firm believer in Amsoil products, been using them in everything for years. They offer a product they claim you can pour in your tank that neutralizes ethanol for $5. So I am going to buy 4 bottles of it and try using it and the E10 and see if I keep these higher mileage numbers I am getting now.

I'm basically experimenting trying to find a happy medium where I get the most power, best obtainable mileage possible.

 

ive got a bust in my equations.

what i unintentionally showed was how far you can drive out of your way to save 10 cents per gallon on gas... not what i was trying to show.

really the point was that it is nearly a wash either way. There is a potential cost savings per mile if the %MPG goes up at a faster rate than the %increase in price.

that is to say, you can pay 10% more in price/gallong so long as you are rewarded with at least 10% increase in MPG.

in your case you get about 16% better MPG on non ethanol, so you can afford to pay up to about $4.03. and come out ahead or even. this assumes you don't drive out of your way. the savings go away quickly if you drive out of your way.

speaking strictly from a mony stand point:
Not sure how good you are at math in your head, but if you have a calculator on your phone, just take your e10 price and multiply by 1.15 and that is your benchmark for the regular fuel price. less than that, you save money, more than that and you dont.

with gas prices as high as they are, you will likely see a savings if your mileage difference is over 10%.

 

Thank you, That makes sense. I'm saving but not as much as I thought I was.... I guess I should also take into account that I'm not running that ethanol through my engine so that accounts for something lol.

 

You only made one mistake. You figured both at 20 gallon fillups. However the 23 mpg model would refill 100 miles later than the 18 mpg model. So to compare apples to apples you would only be burning 15.65 gallons instead of 20 for the same number of miles. Now multiply 15.65 times 3.55 equals 55.56 dollars to refill. The 18 mpg model would be 20 times 3.45 to equal 69 dollars to refill. 13 dollars and 44 cents less per each equal number of miles driven to refill. Much larger difference than your .001 cents per mile. Total gallons used for 200,000 mile life at 18 is 11,111.11. Total gallons used at 23 is 8,695. 65 for a difference of 2,415.46 gallons. At 3.45 per gallon you will have saved 8,333.37 dollars. Big big difference.

Now, you check my math. Tell me I am wrong.......

Actually you will save much more.

Plus.....just look at how many fewer times are wasted filling up and driving to the station. Additional savings not even figured in..................

 

but ethanol is good for them

didn't you read my posts?!?!? j/k

i am curious as to why the soot on your tail pipe would go away with the preimum unlead. in all reality, the additional oxygen in the ethanol blend should *prevent* soot by providing additional oxygen for combustion. that's why they use it in the first place, to lower emissions (which it does by every report i've found)

i have heard reports that the ecoboost will use dump additional fuel under boost, in excess of what could be burned, to keep the engine out of spark knock and for cooling. this is also why some get very low mileage while towing through very hilly country.

this would explain the better mileage on the higher octane, and the lack of soot on the tail pipe.

perhaps a fill up of 91octane e10 would tell you something? just a thought.

i still think if you are using 87octane e10, it is because they are using crappy 85 and adding the etnanol to make it 87 .... i think they are just using super crappy gas and the ethanol only improves it to the point where it is usefull. that's my opionion.

Think about it, if you saw 85 octane fuel at the pump, you would never buy it, not unless you are very high altitued and are used to it ... i would never use it regarless.

i think they have to do less work to make lower octane fuels, so they are not as good. less additives, ect .. that's why you pay more for higer octane fuel. now they have a market for their poopy 85 octane swamp gas .... i'm a cynic, what can i say.

 

after i went through it again from a different angle, i came up with that 6-8k range for savings as well.

for some reason my mind just went down the wrong path when i put that together.... really though, like i said, the real point was to show that you cant hardly save anything if you have to drive out of your way. the cost per mile to drive eats up your savings in a hurry.

600-800 bucks a year .... might be worth it ... might not, depends on how you feel about ethanol.

i'll pay the 600 to 800 to support our local economy. i've made no bones about that. others need to choose for themselves. i only hope they do some research before condeming a fuel based on MPG alone. If the world did that, we would all be driving diesels.

 

Don't get me wrong. I am a farmer and I raise corn. I have always supported ethanol. However I have found when traveling down south pulling my 34 ft travel trailer that I gained 2 mpg burning 87 octane non-ethanol over the E-10 89 octane. Now 2 mpg may not look like much but when it jumps you from 7.3 to 9.3 that is a whopping 27 % increase. Well worth the extra 10 cents per gallon. I think there should be a larger differential than 10 cents per gallon between E-10 and regular non-E 87 octane gas. At 10 cents per gallon you are losing not gaining. My personal opinion of course.

 

I think you are correct. I think they are overcharging for the E10. He is using a higher octane with the pure gas too. Here it's 10 cents for each octane upgrade. So it looks like he is paying the same amount per gallon just extra for the 90 octane gas.

 

We have a local chain of gas stations in the Knoxville area called Weigels, and some of them sell 100% pure gas it would seem. What excites me is I know from driving by some of these stations every day that they seem to price their gas exactly the same as the other Weigels in similar locations that sell E-10. I'm going to give this a shot and see what kind of gas mileage I'm able to achieve. I'm currently hovering around 17 with Shell or BP E-10.

 

Aavoxx--I would go inside and ask to make sure it does not have ethanol in the gas. Now-a-days I don't think they have to label the pumps anymore. They can pump E-10 as 87 or 89 octane and don't have to tell us. I am not sure but it would not hurt to ask first.

 

Luckily it's a Tennessee state law that the pumps have to be labeled.

 

It's state law here in Florida as well.... They gotta label the pumps for Ethanol content percentage.

In regards to another post....I ran 93 octane E10 in mine when I first got it and although I did see a small improvement in performance, the mileage didn't increase so I went back to the 87 E gas.