To run my 2005 FEH on E85 I got a plug-n-play converter box from here:
http://www.change2e85.com/servlet/StoreFront

The claims on the site are a bit overstated, however, it does work.
My otherwise stock FEH runs great on E85, just with lower MPG.
I have driven about 1000 miles with E85 in weather from 60'F down to 10'F and it runs great, and runs at lower RPM when climbing hills, and runs at 2200 RPM at 70 MPH which I 'think' is lower than before.

The built-in Ford ( or any car ) ECU has the ability to change the injector pulse length between -30% and +30% from "normal" fuel/air ratio of 1:14.7 for gasoline. ( to adjust for load and altitude for example )

Running at +30% is 'almost' enough to run E85. In fact, your stock, factory FEH can run up to E60 right now.

However, to run E85, you need the injectors to fire +35% longer.
If the ECU tries to pass 25% the computer says, hey, this is unusual, something must be wrong, and a check engine light comes on.

So the factory possible range is about -30% to +30%.
( with -25% to +25% considered "normal" in a 2005... or up to 29% is considered normal in a 2008 )

Here's what the "add on" E85 box does:
It moves the injector range to -15% to +45%.
The car's ECU still controls everything in the car within this new range.
Ford's software is in full control of the air/fuel ratio, and emissions control.
Just now -15% to +45% is now considered the new "normal".
( with plain gas, the car hovers around 0%, and with E10 the car hovers around +4% )

It was much simpler than I expected to run E85.
No hardware change is required.
Just a software "spoof" basically.
The car runs great, and I'm getting about 25 MPG with mostly highway driving in Minnesota winter.
-John

What the web site for the product doesn't tell you is, there is a potentiometer inside the case of the converter, and you can adjust the range from factory ( normally -30 to +30 ) to 0 to +60% and everything in between. It comes out of the box set at -18% to +42% and you should not need to change that. I changed mine to -15% to +45% for no particular reason... just to prove I could!

Pure gas should run the injectors at 0% trim, thus you are O.K. leaving it at -15 to +45. Negative of zero is lean, positive rich... but a positive number is not really rich when you are using E85.

Ethanol needs 1 part fuel to 10 parts air.
Gas needs 1 part fuel to 14.7 parts air.

-John

Can the injector range be read with a scan guage? Is this a good indicator of fuel quality? Or, and indicator of ethanol content? MPG varies with the fuel retailer here is So Cal. And it is seasonly adjusted, too. Arizona fuel almost always provides better mpg.

2008 FWD Escape Hybrid

Would be nice except for the fact it probably totally voids the warranty for any engine problems because it is not what the manual says to use......

I am beyond warranty miles!

Yes, you can use a ScanGauge to monitor things.
-John

I always say that just because you CAN do something doesn't mean you should....


1. Do you know for a fact that the FEH has corrosion-resistant fuel systems with the necessary plastic and rubber parts?

2. I understand that this kit allows you to adjust the "normal" range so the CE light doesn't come on....but how does the vehicle know the appropriate fuel mixture to use? Is it based off the O2 sensors and is that a sufficient measure to determine the appropriate mixture?

-Tim

2006 Mercury Mariner Hybrid AWD
Black with Pebble interior
Premium Package with Nav & Moonroof



Current ODO: 26,152
Typical Drive: 20 min crosstown in heavy traffic (3.5mi there and back twice a day)


532 Gallons of gas saved
That's 10,642 lbs less CO2 emitted

How difficult was the install? Did you DIY?

Ducit Amour Hybridae
Mark Smith
Master Certifited Technician
Tempus non reparabilis fugit
"It isn't pollution that's harming the environment. It's the impurities in our air and water that are doing it."

Best Tank 35.0 MPG

No. I know that ethanol has a pH of about 7.5 and is non-corrosive to most substances. Ethanol, in general, is less corrosive than water. There are only a select few things ethanol is bad for. Natural Rubber is one. I am assuming there are no natural rubber parts in contact with liquid fuel.
Aluminum is another "not recommended" substance. But you find this reference when talking about underground tanks and gas stations, who probably expect their tanks to last longer than 5 years. In all likelyhood, I'll have 200,000 miles on the car, and be ready for a new one before I see any ill effects of ethanol. I expect to have 200,000 miles in about 4 years from now. I'm past warranty miles on everything except the battery. I'd love to hear Ford try to DQ my battery warranty for useing ethanol! PLUS I will not be using ethanol full-time. I can't find it full time.
Ethanol is harmless to steel, stainless steel, and metals except Al, Cu, Pt, Pb. Are there Copper parts in the fuel system? Are there Aluminum parts in the fuel system? Are there Platinum parts in the fuel system? How about Lead?

Before you answer yes, exhaust doesn't count. I mean in the liquid fuel system only. I think Aluminum is the only suspect.

In addition, no one ever uses 100% ethanol. There's always 15% gasoline, usually more. This is akin to having some WD-40 in there for lubrication and protection. So all the above concerns are greatly reduced.

It really is that simple. The O2 sensor, just the first one in the exhaust, pre-catalyst, is responsible for the fuel/air ratio. Yes. The second O2 sensor, post catalyst is there to determine a defective catalyst. The MAP, MAF, and CHT sensors are also used to "refine" the mix, but the O2 sensor is the "primary" input, any time the car is running "closed loop".

Ethanol adds more oxygen. The O2 sensor sees this and says add more fuel, because it thinks the O2 came from air. Which is a reasonable thing to do since ethanol has less energy per unit compared to gasoline. The car does NOT suck in additional air... so the fuel to air ratio gets corrected.

You can DIY. It is plug-n-play with vehicle specific connectors.
The correct connectors for the FEH and probably all newer Fords is: Bosch EV6

I think since the advent of E10 most cars can mechanically handle ethanol. I remember some of the European cars had some trouble with the injectors in the late 80s, but by now most manufactures have reasonable fuel systems. The main problem is the wide fuel ratio needs that a flex fuel vehicle needs. Most have some sensor that detects what kind of fuel and can make the necessary adjustments to the software. I doubt John will have trouble with the ethanol other than switching back and forth since he does not have a fuel sensor to determine the what fuel is running. (I think)

Ducit Amour Hybridae
Mark Smith
Master Certifited Technician
Tempus non reparabilis fugit
"It isn't pollution that's harming the environment. It's the impurities in our air and water that are doing it."

Best Tank 35.0 MPG

Mark, the FEH will adjust to plain gas, or E85, all by itself.
However, this is a slow "learning" process. The directions for the E85 box even say to use one tank of 50/50 before going to all E85.

I think the E85 converter box is not a very smart device.
There is no "ethanol detection" process.
It simply lengthens the injector pulse time.

I was thinking what you were thinking....
If I ever need to move from pure gas ( or pure E10 ) to E85 or the reverse all in one step, I may reach under the hood and adjust the manual trim screw myself... to eliminate most of the slow learning process.

The car will not need to "figure out" what it's burning with a little manual intervention. This is generally, not required, but would help MPG when making large jumps in ethanol percent.

-John