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dan45mcc

3 of the 4 engines tested got better mileage on ethanol

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rufus provided this story that Cindy Z covered over at

http://domesticfuel.com/?p=3522

 

"The new research strongly suggests that there is an ?optimal blend level? of ethanol and gasoline - most likely E20 or E30 - at which cars will get better mileage than predicted based strictly on the fuel?s per-gallon Btu content. The new study, co-sponsored by the U.S. Department of Energy and the American Coalition for Ethanol (ACE), also found that mid-range ethanol blends reduce harmful tailpipe emissions."

 

 

 

 

 

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I have stated that my 2004 4RUNNER gets as good or better gas mileage with a E25-E30 mix.

 

I believe that the ethanol is just another fuel in the 'gasoline' cocktail.  Gasoline is a mix of many types of HC fuels.  The ethanol is helping combust them all.  It also adds octane so that smart ecu's can adjust timing accordingly (knock sensor feedback).

 

A great test would be to measure the actual cylinder pressures in an engine as a function of angular degree and also angular speed.  This would prove out which mix can be the best once timing is optimized for it.

 

I suspect a E30 mix would still require a bit more timing.  But I believe it offers an alternative that we could actually meet.  We can not produce enough ethanol for E85 for the large number of engines we run.  A E30 mix relieves a substantial need and also does not require the flex technology.

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Guest colchiro

Crowbar, where you located? How does it run in the winter with 30%? I traded my '99 4Runner over 6 months ago, but my wife still has one. The Arabs forced me to do it. ::)

 

It's been near 0 in ND/MN with a few dips near -20 (while I was out of town) ;), but supposed to have one more on Saturday while I'm at our Christmas party so can't avoid it.

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Colorado.

 

It is 18 degrees this morning.  I never have any failed starts and it runs fine.  It does take awhile to heat up but I garage my 4Runner anyway.

 

My 4Runner has a wide band O2 sensor in each exhaust manifold of the V6.  It also has a narrowband after the catalytic converter.  I do not know if a earlier version has this.  In any case, the car is very peppy and I have even driven it on higher eth mixtures but I notice mileage does go down.

 

I believe E30 is probably the best for its stock configuration.

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Guest colchiro

I got pretty good mileage with E60 on my Rav4 prior to converting (22 mpg, down from 25 mpg on E10). Not sure how winter starting would have been with E60 tho. Sub-zero temps make you do crazy stuff.

 

I'm still interested in checking my mileage with E30-E60 after getting my a/f meter installed. Considering how I'd have to disconnect wires to my injectors, and winter-blend gas, I think this won't happen until late spring.

 

Documentation that came with my a/f meter suggests that the best fuel economy is at 15.0:1 ratio. I know E85 will let you go leaner, but I'd like to know what the best ratio is at different blends of ethanol.

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30% is where my old wagon likes it. It runs fine on that, and I've even seen some mileage improvement. The last of my current Oxytane is for DB's first trip back to the dyno.

 

As soon as I get this flywheel sitution sorted out, I'll have her back on the road. The Napa guy messed up the dowel holes in my lightweight flywheel  >:(

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Although I run my WRX on 100% E85 almost all the time, It does appear to get about 1 mpg more fuel milage on a slightly lower blend. Its ideal blend is probably 60% -70% but I have not intentionally investigated that.

Since my base fuel mileage when trying to drive economically is just about 19 mpg, adding 1-2 gallons of gasoline will break me in to the low 20's, so that is about a 5% increase in fuel mileage. Given the split in gasoline vs E85 prices in a cost per mile basis it is pretty much a wash, and it is less hassle to just run straight E85.

 

Larry

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Guest colchiro

I decided to put a hold on E85 and learn how to use my new air/fuel meter by trying E30 (with my converter removed) for a while to see how the meter reads when I'm getting awesome gas mileage.

 

I read that the best mileage occurs with a 15:1 ratio on unleaded and since ethanol tolerates a leaner mixture, with a converter that uses the oxygen sensor, I might need to put an adjustable resister between the converter and the o2 sensor to optimize highway mileage. (If I'm wrong and the resistor richens the mixture, then a resistor could be connected to 12 volts and used to pull up the voltage from the sensor.)

 

With E50 at 70 mph without a converter, I noticed that my mixture was bouncing around stoich (14.7+).

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