E85Forum.com

specialgreen

I decided that before shopping for a FlexTek, I should see how far my VW Passat (VR6 engine) will go with ethanol. My goal was to reach at-least 50% E-85. Since our local "regular" gas is E-10, but E-85 is really only E-70 in winter, that would mean that my goal is 40% ethanol in winter (and 47.5% ethanol in summer).

I started with 6 gallons of E-85, in a (supposed) 18-gallon tank, and filled the rest up with "regular" (E-10). So that's 6 gallons * 70% (winter e-85) + 12 gallons * 10% ethanol, or 5.4 gallons of ethanol out of 18 total gallons... E-28 (27.78% ethanol).

After I had run the tank down a bit, I added 4 gallons E-85, which was just enough to fill it. This is where it "ethanol math" gets complicated! Of the 14 gallons that was in the tank before, there was 14 * 27.78% = 3.89 gallons of ethanol. Of the new 4 gallons of E-70, there was 4 * 70% = 2.8 gallons of ethanol. So now there were 6.69 gallons of ethanol in the (full) 18 gallon tank... 37% ethanol.

So now I have a sticky note on my dashboard reminding me that my current fuel is E-37... pretty close to the winter goal of E-40. I will see how much ethanol I can add before driving performance is impacted. After I went from E-28 to E-37, I seemed to notice that there was a little less torque at low RPM. I have to give it a little more gas when popping the clutch, or at least I think so. This is very subjective. Regardless, if there is a difference with E-37, it is very manageable.

nybbe_gefle · Joined: 02 Aug 2005 Posts: 5 Location: Gävle, Sweden

Early 90´s VW are known to accept high % of Ethanol. What year was the Passat born?? Overall Bosch Motronic Fuel/ignition manegmentsystems are usually quite generous to adapt to high % Ethanol. I´ve got a Motronicsystem called 1.8 in my 95 Volvo 960 and it run perfectly to approx E65.

//David
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specialgreen · Posted: Wed Nov 02, 2005 6:52 pm Post subject:

It is a 1995 Passat GLX. I think I will try a tank or two at E-40 before going higher. The next step after E-40 would be maybe 2 gallons E-85 (70%) per 1 gallon regular (10%), or E-50.

But it may take me a while to use-up the tank, as I'm still riding the E-85 motorcycle when I can.

specialgreen · Posted: Sat Nov 26, 2005 11:16 pm Post subject:

I ran two tank-fulls through with 50% "E-85". It's actually 70% ethanol here in winter... which makes it E-40 when blended 1:1 with regular (10% ethanol here):

(.7 + .1) / 2 = 40% ethanol

Then I switched to mixing 2 gallons "E-85" with 1 gallon E-10. That's ((2 * .7) + .1) / 3), or E-50. It feels as though when I pop the clutch, I need to give the engine a little more gas, and I need to keep the revs a little higher, or else the engine feels as though it may die. Shifting from 1st to 2nd feels just fine.

Other than that, the VW VR6 engine has been driving fine through almost 2 gastanks' worth of E-50.

My next experiment will be mixing 3 gallons of "E-85" with one gallon of "regular", or:
((3 * .7) + (1 * .1)) / 4 = E-55
Having run with E-50 for a couple of tanks, that doesn't sound too extreme . Smile

chenely63 · Joined: 09 Aug 2005 Posts: 27

when does E 85 go to E 70?
I been running my 1996 ford ranger four cly on what I though was about a 50% mixture but at 70 it would be a lot less,,
Do you know of a sensor that you could use to have a running check on the mixture?
Leo

specialgreen · Posted: Sun Nov 27, 2005 11:36 pm Post subject:

It appears that "E-85" may be 70% ethanol from November through March, see http://e85forum.com/post-30.html#30 .

There doesn't appear to be any requirement that the blend be changed seasonally. Probably only the local blender would know whether the blend was adjusted to 70%, and when. As E-85 continues to increase outside of the Midwest, there may be parts of the country that run on 85% year-round.

One practical way to test the amount of gasoline in "E-85", would be to put 5cc of fuel into a 10cc test tube, and add water until the fuel separates (2cc water should do it). The ethanol/water mix will go to the bottom, and the gasoline will float on top. With E-70, the gasoline layer would be 1.5cc thick; with E-85, it would be only 0.75cc thick.

The GM FFVs have a sensor in the gas tank that reads the ethanol level of the fuel. It might be integrated into the fuel pump(?). It might be possible to hook something like that into the fuel injection fuel return line on a non-FFV to give a read-out.

chenely63 · Joined: 09 Aug 2005 Posts: 27

do you know what year and model that has the sensor in the gas tank?
do you know of any place where a sensor for ethanhol can be bought?
thanks
Leo

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

Ethanol (77° F) 24.3 k

Dielectric Constant (k) is a number relating the ability of a material to carry alternating current to the ability of vacuum to carry alternating current. The capacitance created by the presence of the material is directly related to the Dielectric Constant of the material.

Using this value there should be a way to use a ohm meter to measure the resistance of ethanol and figure out the concentration in gasoline right?
This is what a ethanol sensor should do as well?

I've searched online for a resistance chart for E85 with no luck.

hotrod · Joined: 19 Apr 2005 Posts: 533 Location: Colorado

You might find some interesting info here.

http://www.gmtechlink.com/images/issues/arcv_pdf/3_00_e.pdf

Sounds like the sensor uses the change in fuel dielectric-constant to alter capacitance in an oscillator. Hmmmm this might be a simple sensor to "graft" into a non-GM vehicle if the support electronics are not too demanding.

I have not stumbled across any further info on the sensor itself, ie 5V supply self contained or if it needs ECU support to function?

The variable frequency output would be easy to build control circuitry around.

By very cold climates I assume they are refering to near arctic environments. I've been told by the E85 wholesaler in this area and a second regional supplier that in this part of the country they drop the mixture to 75% ethanol in the winter time.

I'm pretty sure that adjustment is made on a local level determined by typical local winter temps.

Larry

chenely63 · Joined: 09 Aug 2005 Posts: 27

interesting article on the E 85 fuel sensor
would like to find a sensor I could use with my flex tek uint I am running on a ford ranger.
didnt know you should not use a fuel additive with alochol, say it may sto[p up the fuel strainer on the pump?
Leo

specialgreen · Posted: Sun Dec 04, 2005 9:29 pm Post subject:

I have had fuel leak into my oilpan (stuck float needle in a carb), both with gasoline fuel and with E-85. With gasoline mixed-in, the oil was much thinner than usual, and smelled horrible. But with E-85, when I drained it into a pan, it seemed to separate into separate ethanol and oil layers.

So I can imagine that there are additives that would not mix well with E-85. Maybe that's what they are warning against? FWIW, I tested Sta-Bil by mixing some with E-85 in a jar, and left it on a shelf in the garage for 6 months. It showed no signs of separating. So some additives mix well with E-85.

specialgreen · Posted: Tue Dec 06, 2005 10:27 am Post subject:

When I started the VW this morning, it was -6F. It turned over a couple of times, but seemed to start and warm-up just fine. (still burning 2:1 mix of E-85 and regular gas).

chenely63 · Joined: 09 Aug 2005 Posts: 27

15 below in spencer Iowa this morning
been running about half and half reg gas and E 85 or what ever
1996 ford ranger four cly
started ok, maybe a little slower but ok
Leo

farm2fuel · Joined: 17 Sep 2005 Posts: 5

The timeframe of E70 is varied for each geographical location - http://www.e85fuel.com/pdf/e85_technical_booklet.pdf It is a requirement to make this change in accordance with the ASTM fuel standard for E85, which is also included.

BURNALCOHOL · Joined: 19 Oct 2005 Posts: 50 Location: Raymond,NE

Flextek converters do not need in the fuel type sensor to adjust for different ethanol mixtures. The car's computer adjust the mixture from the O2 sensor. Most new FFV use the O2 sensor now to adjust for fuel mixtures also.

As far as the sensor to find what amount of ethanol is in the fuel. You can use a hydrometer to read specific gravity. Just float it in the fuel and compare the SG of straight fuel to ethanol's SG.
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Jeremy Nicholls