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How does taurus flex fuel vehicle know when E85 is in tank? If E85 has 30% less energy than gas, does computer increase fuel flow and tweak injector timing to deliver more fuel per rev?

FFVs (Flexible Fuel Vehicles) have an engine control computer that recognizes the mixture of fuel so the ignition timing and fuel flow rate can be optimized for the fuel mixture being used. In simpler terms…the vehicle computer takes care of running the engine just like a non-FFV vehicle. The engine control computer in an FFV vehicle is completely different than a regular fuel vehicle computer though.

You think using e85 might affect my occasional rich idle condition? Seems to me a flex car might run into fueling issues that a non-flex car may not see

I’m pretty sure the computer adjusts the air fuel mixture until the oxygen sensor in the exhaust indicates a stoichiometric fuel air mixture, that’s how it knows that you are running E85. It’s not like your tank has either E85 or E10 or pure gasoline. If you topped off half a tank of E0 with E85, what you have in the tank is actually E42 when the two mix and the computer would have to adjust for that.

If you have an occasional rich idle condition, you need to fix the real problem, not try to Band-Aid it with E85.


May we assume that you are actually filling up with E85?

May I ask why you’re using it, considering that it actually has less energy?

It doesn’t seem worth all the hassle, in my opinion

Or did you just ask a hypothetical question?

I believe B.L.E. is correct. It isn’t that the ECU “recognizes” the higher level of ethanol, it’s that the programming and the injection system has the capacity within its range to properly adjust for the higher oxygen content in the ethanol-based exhaust.

B.L.E. is right on the money. Unless you run your car exclusively on E85, it will always have a mixture of fuel in the tank that has less than 85% ethanol. Flex fuel vehicles are made to handle any fuel mixture between E0 and E85.

Boy you have to be careful now if you don’t have a flex fuel vehicle. I pulled into a Coop station in rural Minnesota a couple days ago and the last island had just green (diesel) and yellow (E85) nozzels. I had to back up to get to a black nozzel. Of course they have small print telling you to just use in flex fuel but most people don’t read all the small stickers on the gas pumps. At least they are color coded. I told my wife to make sure you never use yellow or green, just black. I don’t know about people that are color blind-I think they’d all look gray or brown.

@Bing to make matters worse…most gas nozzles sold have a black handle. A new Speedway opened in our area and on the first day open I noticed that all the nozzles were black except for the diesel pumps. When I told the manager…his face went white. All was well though because they were still waiting on the E85 delivery. If they had full E85 tanks…there would have been major problems I’m sure.

I think the most rational course would be to use E85 and biodiesel in agricultural equipment. that way farmers would have the ability to control their fuel supply and if it caused too many problems they would be the ones suffering.

seems like a good check and balance

I have yet to see any stations here in NH or MA that sell E-85. But there are Flex-Fuel vehicles sold here.

I don’t see many stations selling E85 either. I see them most when I travel through corn country. Everywhere else, it’s just a gimmick, because when you add transportation costs, corn-based E85 is an economic failure, even with government subsidies.

I haven’t seen any either… but I always check the pump carefully so it doesn’t sneak in on me. Accidentally filling the tank with E85 is one mistake I’d rather avoid.

Does any just average everyday driver even use E85 by voluntary conscious choice to begin with? Or why? For that matter. I have not seen any real good rational argument for it.

Nobody has. It’s purely political. The agricultural lobby and it’s subsidiary the Ethanol Producers Lobby have lots of pull in the beltway. The lobbyists write the legislation, convince one of the pols that it benefits him/her to sponsor it, then spend enormous amounts of money convincing enough pols to pass it that voting “yea” will benefit them personally.

Lobbies aren’t just a smattering of lawyers promoting legislation. They’re enormous machines that actually create legislation. As long as the beltway is filled with pols whose main goal is getting reelected, the problem will persist.

There are 7 stations that sell E85 in MD, all are in suburban DC. I’m surprised that there are any. They must be located near where Corn Belt legislators live.

E85 gas prices around here are around $2.88 a gallon. That’s sounds like a great deal for someone with a flex fuel vehicle until you do the math. I can get regular for around $3.09 a gallon and would buy it instead if I owned a flex fuel vehicle.

Anyone who lives in Corn Country benefits from the use of E85 either directly or indirectly, so yes, there are folks who voluntarily use E85. Of course there are. To ignore the inherent self interest involved would be foolish. Everyone else who does so is probably doing it for ideological (perceived energy independence) reasons.

I AGREE that the statements @Whitey made are correct

But I don’t LIKE the idea of E85. I think farmers should be growing products to fill our bellies, not our tanks

It’s a real shame things are so mixed up

This is one case where I agree with someone’s comments, but I don’t like them

I like @Whitey just fine. But I don’t like the comments, BECAUSE they are true, and I agree with them. Because I don’t like the truth that he is pointing out.

I’ve got no problem with @Whitey. He’s just the messenger

This proves to me that we DO need separate like and agree buttons

In case I’m confusing, this was not an attack on anybody

On a slightly different note, the fist cellulosic ethanol plant started production last Wednesday. When it ramps up to full production, it will produce the ethanol equivalent do 2.6 million BTUs per year. I hope this works. It should make corn kernels more attractive as food again.