Real Gasoline, not Ethanol

That is not a rounding error. One in 200, e.g. the ratio between tobacco and corn, would be.

The USDA chart posted above by 2k1Toaster suggests a much high fraction. Why do you exclude that?

GM genetically modified vs Gen Motors. Wow Virgina would go wild for that. A few years back I wrote to my Senator about an energy bill, I was opposing for some reason, and he wrote back and said he had to pass the bill because Switchgrass was going to be a bonanza for Virginia. Took me a while to figure out there must be a need to refill Tobacco fields. But OK, GMod Tobacco.

A while back I did a six-month test on E10 blends versus real gasoline. Here's the results:

A few disclaimers here:

1) At the time, I was driving a 2000 Toyota Echo with a 5 speed - the EPA claims I would get 34/41 - I was hypermiling at the time and my drive was 90% highway miles. Hence the extremely high MPG.

1a) As you can tell, I stopped using E10 after the results became absolutely clear - it simply wasn't worth the extra cost [my being a broke college student at the time] to keep throwing money down the toilet like thus.

2) However, this may nevertheless corroborate with the Prius since both the Echo/Yaris and 2nd gen Prius have similar engines (1NZ-series).

3) Insert your generic "Please don't repost without my express permission" clause here.

...??? not energy industry fault, Congress mandated ethanol to make gasoline burn cleaner. That was indeed a bit misleading, better known at the time as "bad science" on the part of Congress.

LOL, and who bribed, er, lobbied congress to require ethanol in gasoline?

Eh, I can't really defend what I said four-plus years ago when I first did this test. I suppose now, that I'm a bit older and wiser, I should say ADM and its lobbyists in Washington. But either way, it simply doesn't bode well for Americans in general if ethanol really is as bad an idea as it seems.

Looks to me like you said it at 5:33PM today, about 1/2 hour ago.

I understand what you meant above, I just couldn't resist

ADM I assume? I am confused by your question but the corn states and farming lobbies wanted the ethanol...that's where the push was from.

Code:

[B][U]E10[/U][COLOR=white]______________________[/COLOR][/B]
             03/20/2008 - 48.743 MPG,    306.3 miles, 6.284 gallons
             03/28/2008 - 49.926 MPG,  271.6 miles, 5.44 gallons
             04/09/2008 - 51.964 MPG,   498.9 miles, 9.599 gallons
             06/08/2008 - 46.460 MPG,   253.3 miles, 5.452 gallons
             06/09/2008 - 50.159 MPG,  236.2 miles, 4.709 gallons
             06/14/2008 - 51.749 MPG,  470.5 miles, 9.092 gallons
 [B]Average: [U]50.197 MPG[/U], 2036.8 miles, 40.576   gallons[/B]
 
 
 [B][U]Straight Gas[/U][/B]
04/22/2008 - 58.484 MPG,  476.7 miles, 8.151 gallons
05/18/2008 - 56.891 MPG,  480.1 miles, 8.439 gallons
05/22/2008 - 56.813 MPG,  501.6 miles, 8.829 gallons
06/30/2008 - 56.310 MPG,  461.6 miles, 8.201 gallons
07/15/2008 - 61.618 MPG,  527.7 miles, 8.564 gallons
07/25/2008 - 61.267 MPG,  505.7 miles, 8.254 gallons
         08/18/2008 - 59.096 MPG,  569.8 miles, 9.642 gallons
 [B]Average: [U]58.642 MPG[/U], 3523.2 miles, 60.08 gallons[/B]
 
 
 [B]Fuel Economy Loss Due to E10: 16.82%[/B]

Almost 17% is a truly remarkable loss of gas mileage for just 10% ethanol. I can say for certain that I don't get anywhere near that type of result with E10. I did get a 7% drop in fuel efficiency with a tank of E10 from one particular petrol station, but generally it's more like 3% for me.

While not wanting to be overly critical of your results, I wonder if this type of test can really be trusted unless carried out using a scientific "double blind" type procedure? Particularly given that the person doing the testing often has an "axe to grind" against ethanol fuel in the first place.

Time and fuel permitting, I can certainly run the test again once I've got my Prius. I'm not a hundred percent sure I could find real gasoline anymore? I freely admit that this test is nowhere near scientifically sound - after all, it's only one vehicle over a dozen or so fill-ups. I would have used a much, much larger sample size if it was available.

What really grinded my gears at the time was that the locally available E10 fuel was (and often still is) 20-30 cents more expensive than real gasoline less than 10 minutes away. Problem is, the three-county area was the only area (next closest was Chicago and possibly Louisville) that used the boutique fuel, which meant higher prices even though state taxes were actually lower.

The worst fuel economy I ever saw was a 29 MPG tank -when I filled up at a Sunoco on the Pennsylvania Turnpike. I'll never do that again.

Picture courtesy of hobbit:

Ethanol is required all year long here in Oregon with
a 10% blend.

When I used gas with no ethanol I noticed a noticable difference of
more mpg.

This was quite noticable when we
were in Reno Nevada, I was at the last pip and filled to the top
of the neck with regular non ethanol gas.

About 3-4 miles I notice the mpg gauge was reading much higher than with Ethanol gas and that tank was 58 mpg calculated. The Ethanol tank was 53 mpg calculated. That is a lot more than a 3% improvement.

Ethanol is not, I repeat not a wonder fuel. If it was so
great why does the U.S. EPA not use Ethanol gas when it is
testing cars for official EPA MPG ratings......?

There is one scientific argument that there is probably no fundamental benefit for putting oxygenates in gasoline. Having said that, it can of course be done. Ethanol is not too shabby as far as oxygenates go, high octane, non-toxic, biodegradable, not too volatile, good gasoline blending component. Other things like MTBE are less benign ecologically.

I wish EPA would do an E10 or E15 cycle as part of the test so we would finally have some decent data on impact.

I'll probably do a couple of tanks of E10 sometime soon and document my MPG here.

We get E10 a little cheaper than non-ethanol petrol, it's only a few percent cheaper but it's usually enough to just about offset the lower fuel mileage. Generally I prefer non ethanol fuel but I dont mind running the occasional tank of E10 through as bit of a cleaner.

I dunno, maybe we get better quality E10 here or something, but I rarely notice anything more than about 0.1L/100km increase in fuel usage (approx 2.5%) with E10.

This corroborates your numbers a bit - a state senator had a drop from 40 to 33 MPG - a drop of some 17% as well.

Oregon's Ethanol Mandate Under Fire · OPB News

I very recently purchased a 2009 Prius and have been reading the forum to learn more about it. I drove a 1.8T VW Beetle for years and tracked my mileage. I usually average over 30mpg using gasoline. Using ethanol, I get 4-5mpg less. Here in Big Wonderful we pay the same for either at the pump. I still haven't educated myself too much on the bladder tank - just found out about it here. I drove it over 1000 miles on Thursday from Phoenix to Casper - wow, what a gorgeous drive! Sedona and Moab were most memorable. One of the reasons I came here was the gas mileage was all over the board. I didn't get a manual so figuring out all the electronics has been an ordeal.

Think you are saying 4-5 MPG 15% loss with E85 which is not bad.
Not sure if 2009 still had the bladder tank but if so that adds more variation to your MPG calcs so you sort of need to average. I downloaded much Gen-II useful info from user John1701a if he still has a web site you can check it out or maybe his stuff is posted here.

:welcome: feel free to search posts and ask questions on anything you cannot locate. you can download a manual for your car. all the best with your new prius!

EPA test cars here at their facility in north Ann Arbor, MI, I believe the only gas you can get with Ethanol in Michigan is Sunoco. I believe it dries out wet engines. Some people who's engines run wet will use Sunoco religiously. Other people use Sunoco once every 6 months to dry it out. Sunoco once caused my engine light to come on in my camry so I've never been back since, a shame since they had the best and cheapest car wash in town.
I do believe gas stations with ethanol have to post a warning on the pump letting you know you are about to put garbage in your tank, allowing you to make an escape to find better gas.

Absolutely buy a copy of the correct year Owner's Manual online or from a dealer, and read it. It's full of stuff you need to know. Also get Toyota's (not a dealer's!) Scheduled Maintenance Guide. You can easily find that online.

And unless you like running pointless possibly-expensive uncontrolled experiments *don't* run E85 in a Prius. The fuel system components are not designed for it. E10 is fine and helps keep everything dry and clean.

Interesting article but the state senator's E10 MPG loss in her Camry Hybrid is too big. She said she went from 40 to 33.6 MPG but the 40 reading sounds high for her car. Apparently what is happening is some states like Oregon are mandating E10 even though it is not required by EPA. I don't like that, but as stated in the article, Oregon thinks they see $$$ benefit so they are doing it.