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Tom N · 01-09-2009, 04:14 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by NeilV:
On my 2001 F53 20,000lb chassis on my 3,600 mile fall trip I averaged over the 3,600 miles 10 on straight gas, 8 on up to 10% ethanol and 6 on up to 15% (it was that or nothing) ethanol.
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I have never seen 15% ethanol. Where did you buy that and how was it labeled??

Tom

NeilV · 01-10-2009, 01:35 AM

Up in the mountains on the way back from New England. It did not have an E85 label on it just a sticker disclosing "contains up to 15%...." I did not record the location just the miles.

Tom N · 01-10-2009, 06:07 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by NeilV:
Up in the mountains on the way back from New England. It did not have an E85 label on it just a sticker disclosing "contains up to 15%...." I did not record the location just the miles. </div></BLOCKQUOTE>

If it was 15% ethanol it certainly would not have an E85 label. E85 is 85% ethanol and is for dual fuel vehicles only.

I have no idea why 15% ethanol would be offered as all vehicles that are not dual fuel can only use 10% max ethanol.

-Tom

Noelj · 01-14-2009, 06:34 AM

We are seeing a lot of it here in Tennessee also. I can tell the difference in power and mileage. My HHR gets 32 MPH highway with 100% gasoline, only 29 MPH on 10% corn.

MtManLee · 01-14-2009, 07:46 AM

Someone said you cannot notice a difference in mileage? Seems my saturn drops from 2 to 5 mpg with 10%. New York was talking of doing away with it since there was such a problem with mileage drop. My past vehicle a sonoma pickup would not run on 10%. It would chug and smoke and stink. But would be fine on regular unleaded.

RustyJC · 01-14-2009, 08:21 AM

When the EPA imposed the 10% ethanol requirement in the Houston metro area, mileage on my commute to work dropped from a long term 22 MPG back to 20 - 20.5 MPG in my Acura 3.2TL-S. E10 has fewer BTUs per gallon, so it requires more gallons to do the same work.

Rusty

jspande · 01-14-2009, 08:45 AM

It was mentioned that Ethanol has 75% of the energy content that gas has. Therefore, with a mixture of 10% Ethanol - 90% gas you would expect a 2.5% drop in mileage. A vehicle that gets 30 mpg with gas then would get 29.25 mpg on 10% ethanol. If you're getting results much different than that, either your measurement is off (likely, since it's extremely difficult to make accurate comparative measurements - wind direction and speed identical, traffic conditions identical, etc.) or you should take your vehicle in for a tuneup. Values like 10% - 20% drop make no sense and indicate something is wrong either with the vehicle or the measurement.

RustyJC · 01-14-2009, 09:08 AM

Ethanol = 75,700 BTU/gallon LHV

Gasoline = 115,000 BTU/gallon LHV

E10 = (0.1 x 75,700) + (0.9 x 115,000) = 111,070 BTU/gallon LHV

E85 = (0.85 x 75,700) + (0.15 x 115,000) = 81,595 BTU/gallon LHV

Rusty

Tom N · 01-14-2009, 03:52 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jspande:
It was mentioned that Ethanol has 75% of the energy content that gas has. Therefore, with a mixture of 10% Ethanol - 90% gas you would expect a 2.5% drop in mileage. A vehicle that gets 30 mpg with gas then would get 29.25 mpg on 10% ethanol. If you're getting results much different than that, either your measurement is off (likely, since it's extremely difficult to make accurate comparative measurements - wind direction and speed identical, traffic conditions identical, etc.) or you should take your vehicle in for a tuneup. Values like 10% - 20% drop make no sense and indicate something is wrong either with the vehicle or the measurement. </div></BLOCKQUOTE>

My mileage figures generally agree with your calculations.

And I'm waiting to hear about that 15% ethanol.

Tom