Maybe a fuelish question?

Turtle n Peeps wrote:

agesilaus wrote:

oldmattb wrote:
Toyota Echo driving from Houston to Atlanta and back several times, I noticed a drop in mileage from 43 highway to 39 highway. I came to realize it was the alcohol in the gas. In this case, ten percent alcohol reduced mileage by ten percent.

Matt B

That shows the danger of informal testing. You are saying that you got no energy from that 10% ethanol. Other factors like vehicle loading, driving style and wind might also affect the results.

This^^^^^.

With modern engines computers always keep fuel at the best stoichiometry ratio for the fuel.

For gasoline that is 14.7 to 1.
For ethanol it's 9.0 to 1.
For methanol it's 6.2 to 1.
For E85 it's right at 9.5 to 1.

Anytime you mix a fuel with less energy with one that has more energy you will end up with a fuel that get less MPG.

With E10 that is right at 3 to 4% less miles / gallon.

The good thing about E fuels is they will make more power than straight gasoline...........and that makes me :)

So with the higher cost of straight gas over E-10 against 4% gain in mileage it's about no difference money wise?

200 miles with 21 gallons of e-10 =9.52mpg vs .84 more mpg for regular gas or 10.36?

agesilaus wrote:

oldmattb wrote:
Toyota Echo driving from Houston to Atlanta and back several times, I noticed a drop in mileage from 43 highway to 39 highway. I came to realize it was the alcohol in the gas. In this case, ten percent alcohol reduced mileage by ten percent.

Matt B

That shows the danger of informal testing. You are saying that you got no energy from that 10% ethanol. Other factors like vehicle loading, driving style and wind might also affect the results.

At that rate running E85 in a Toyota Echo would return about 5 mpg or so?

agesilaus wrote:

oldmattb wrote:
Toyota Echo driving from Houston to Atlanta and back several times, I noticed a drop in mileage from 43 highway to 39 highway. I came to realize it was the alcohol in the gas. In this case, ten percent alcohol reduced mileage by ten percent.

Matt B

That shows the danger of informal testing. You are saying that you got no energy from that 10% ethanol. Other factors like vehicle loading, driving style and wind might also affect the results.

This^^^^^.

With modern engines computers always keep fuel at the best stoichiometry ratio for the fuel.

For gasoline that is 14.7 to 1.
For ethanol it's 9.0 to 1.
For methanol it's 6.2 to 1.
For E85 it's right at 9.5 to 1.

Anytime you mix a fuel with less energy with one that has more energy you will end up with a fuel that get less MPG.

With E10 that is right at 3 to 4% less miles / gallon.

The good thing about E fuels is they will make more power than straight gasoline...........and that makes me :)

The 10% ethanol in regular fuel will not harm engines, large or small, when used before it has time to separate. It is the long term effect of stagnant alcohol in the fuel that causes damage to fuel lines, o-rings, seals, etc. Fuel stabilizers, such as Stabil, are generally not effective in stopping the danger of fuel-water-alcohol separation. Unless the formula has changed in the last year or so, Stabil (and most other common similar products) actually contain alcohol. There are a few which don't have alcohol and are actually useful. The reason why smaller engines, like lawnmowers, outboards, generators, etc. run better on non-ethanol is because typically the pure gas being sold is a higher octane.

Locally, there are multiple sources for 90 octane non-ethanol fuel. A couple of years ago, the price was much higher, but now it's leveled into being about 40 cents more than standard 87 octane. I choose to run it in all of my non-car engines. For about a one-year period, I ran nothing but non-ethanol 90 octane in my 2007 Silverdao with 5.3. My results were almost consistently 10-12% better fuel mileage. I felt that the truck did indeed run better when using it.

Dave H M wrote:
I don't even know if you can find pure gas around here. At the air port, sure,

I am glad i do not have the problems with E10. I run it in everything and nary a problem. It sets all winter in the lawnmowers with stabil and varoom in the spring. Weed eater and chin saws eat it like candy. And my chain saws are antiques.

There is a web site that lists places that sell non-ethanol gas by town and state. I don't remember the name.

I have had problems in the past with small engines running ethanol treated with Stabil. It was not winter that gave me problems, it was summer heat.

kaydeejay wrote:

agesilaus wrote:
Ethanol gets 20-25% lower mileage than pure gasoline. So if you are burning 85% gas/15% EtOH then you'd get 3-4 mpg less than pure gas. I think that's what the OP was asking.

That's the way I read the question and I agree with the comment.
What Premium does NOT have Ethanol? I thought the Feds legislated 10% in ALL gasoline.:h

In town a few stations have non-ethanol premium. If you drive to Heston the Casey's has regular without ethanol.

Not all gas has ethanol but it cost more.

agesilaus wrote:

oldmattb wrote:
Toyota Echo driving from Houston to Atlanta and back several times, I noticed a drop in mileage from 43 highway to 39 highway. I came to realize it was the alcohol in the gas. In this case, ten percent alcohol reduced mileage by ten percent.

Matt B

That shows the danger of informal testing. You are saying that you got no energy from that 10% ethanol. Other factors like vehicle loading, driving style and wind might also affect the results.

Not so fast. I've heard of many people claiming a 10% drop. In an engine designed for pure gasoline, the alcohol can trick the computer into an incorrect air/fuel ratio which can waste more than the energy available in the alcohol. Anecdotal? Sure, but enough anecdotes starts to become truth.

I don't even know if you can find pure gas around here. At the air port, sure,

I am glad i do not have the problems with E10. I run it in everything and nary a problem. It sets all winter in the lawnmowers with stabil and varoom in the spring. Weed eater and chin saws eat it like candy. And my chain saws are antiques.

45Ricochet wrote:

kaydeejay wrote:

agesilaus wrote:
Ethanol gets 20-25% lower mileage than pure gasoline. So if you are burning 85% gas/15% EtOH then you'd get 3-4 mpg less than pure gas. I think that's what the OP was asking.

That's the way I read the question and I agree with the comment.
What Premium does NOT have Ethanol? I thought the Feds legislated 10% in ALL gasoline.:h

We have several stations with premium non-ethanol but you pay a fine price for it. It seems to help the small engines last longer. I run it for the small generator for the house, chain saws, trimmers, blowers, my little ATV Mule and lawn mower.
Generally speaking non-ethanol will get you better mileage but the higher cost would offset that extra mileage.

This is what brought the question up. I buy non-ethanol fuel for my small engines because they sit a lot. Around town the only non-ethanol fuel is premium unload. Treat the fuel with Sea Foam in the 29 gallon TH tank. After a year I pump the unused fuel into the truck. It seemed to run better but did not check mileage.

With the 91 octane over 87 and no ethanol wondered what results others have had. I have always been told octane would not make a difference but the truck did run better.

The truck is a 6.8 V-10.

Is all premium non-ethanol?

Anyway, Ford recommends premium for the 3.5L EcoB when towing heavy, so I switched to it.

9K km, regular, 9.88mpgUS
12K km, premium, 10.68mpgUS

So 7.8% improvement when towing. Not enough to pay for it but maybe there's something else worthwhile in the Top Tier's premium secret sauce.